Bluehill 3 Advanced Training Manual

Training Manual M18-16254-EN Revision A

The difference is measurable ®

Electromagnetic Compatibility

Where applicable, this equipment is designed to comply with International Electromagnetic Com-patibility (EMC) standards.

To ensure reproduction of this EMC performance, connect this equipment to a low impedance ground connection. Typical suitable connections are a ground spike or the steel frame of a building.

Proprietary Rights Notice

This document and the information that it contains are the property of Instron. Rights to duplicate or otherwise copy this document and rights to disclose the document and the information that it con-tains to others and the right to use the information contained therein may be acquired only by written permission signed by a duly authorized officer of Instron.

Trademarks

Instron®, Instron Logo, Dynatup®, Shore®, Wilson®, Rockwell®, and Brale® are registered trademarks of Instron. Satec™ and other names, logos, icons, and marks identifying Instron products and services referenced herein are trademarks of Instron. These trademarks may not be used without the prior written permission of Instron.

Other product and company names used herein are trademarks or trade names of their respective companies.

Training Manual

© Copyright 2009 Instron

Worldwide Headquarters

Instron825 University Avenue

Norwood, MA 02062-2643United States of America

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Preliminary Pages

General Safety Precautions

Materials testing systems are potentially hazardous.

Materials testing involves inherent hazards from high forces, rapid motions, and stored energy. You must be aware of all moving and operating components that are potentially hazardous, particularly the actuator in a servohydraulic testing system or the moving crosshead in an electromechanical testing system.

Whenever you consider that safety is compromised, press the Emergency Stop button to stop the test and isolate the testing system from hydraulic or electrical power.

Carefully read all relevant manuals and observe all Warnings and Cautions. The term Warning is used where a hazard may lead to injury or death. The term Caution is used where a hazard may lead to damage to equipment or to loss of data.

Ensure that the test setup and the actual test you will be using on materials, assem-blies, or structures constitute no hazard to yourself or others. Make full use of all mechanical and electronic limits features. These are supplied to enable you to prevent movement of the actuator piston or the moving crosshead beyond desired regions of operation.

The following pages detail various general warnings that you must heed at all times while using materials testing equipment. You will find more specific Warnings and Cautions in the text whenever a potential hazard exists.

Your best safety precautions are to gain a thorough understanding of the equipment by reading your instruction manuals and to always use good judgement.

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Preliminary Pages M18-16254-EN

Warnings

Hazard - Protect electrical cables from damage and inadvertent disconnection.

The loss of controlling and feedback signals that can result from a disconnected or damaged cable causes an open loop condition which may drive the actuator or cross-head rapidly to its extremes of motion. Protect all electrical cables, particularly trans-ducer cables, from damage. Never route cables across the floor without protection, nor suspend cables overhead under excessive strain. Use padding to avoid chafing where cables are routed around corners or through wall openings.

High/Low Temperature Hazard - Wear protective clothing when handling equipment at extremes of temperature.

Materials testing is often carried out at non-ambient temperatures using ovens, fur-naces, or cryogenic chambers. Extreme temperature means an operating temperature exceeding 60°C (140°F) or below 0°C (32°F). You must use protective clothing, such as gloves, when handling equipment at these temperatures. Display a warning notice concerning low or high temperature operation whenever temperature control equip-ment is in use. You should note that the hazard from extreme temperature can extend beyond the immediate area of the test.

Crush Hazard - Take care when installing or removing a specimen, assembly or structure.

Installation or removal of a specimen, assembly, or structure involves working inside the hazard area between the grips or fixtures. Keep clear of the jaws of a grip or fixture at all times. Keep clear of the hazard area between the grips or fixtures during actuator or crosshead movement. Ensure that all actuator or crosshead movements necessary for installation or removal are slow and, where possible, at a low force setting.

Hazard - Do not place a testing system off-line from computer control without first ensuring that no actuator or crosshead movement will occur upon transfer to manual control.

The actuator or crosshead will immediately respond to manual control settings when the system is placed off-line from computer control. Before transferring to manual control, make sure that the control settings are such that unexpected actuator or cross-head movement cannot occur.

Robotic Motion Hazard - Keep clear of the operating envelope of a robotic device unless the device is de-activated.

The robot in an automated testing system presents a hazard because its movements are hard to predict. The robot can go instantly from a waiting state to high speed operation in several axes of motion. During system operation, keep away from the operating envelope of the robot. De-activate the robot before entering the envelope for any pur-pose, such as reloading the specimen magazine.

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Preliminary Pages

Warnings

Hazard - Set the appropriate limits before performing loop tuning or running waveforms or test.

Operational limits are included within your testing system to suspend motion or shut off the system when upper and/or lower bounds of actuator or crosshead travel, or force or strain, are reached during testing. Correct setting of operational limits by the operator, prior to testing, will reduce the risk of damage to test article and system and associated hazard to the operator.

Electrical Hazard - Disconnect the electrical power supply before removing the covers to electrical equipment.

Disconnect equipment from the electrical power supply before removing any electri-cal safety covers or replacing fuses. Do not reconnect the power source while the cov-ers are removed. Refit covers as soon as possible.

Rotating Machinery Hazard - Disconnect power supplies before removing the covers to rotating machinery.

Disconnect equipment from all power supplies before removing any cover which gives access to rotating machinery. Do not reconnect any power supply while the cov-ers are removed unless you are specifically instructed to do so in the manual. If the equipment needs to be operated to perform maintenance tasks with the covers removed, ensure that all loose clothing, long hair, etc. it tied back. Refit covers as soon as possible.

Hazard - Shut down the hydraulic power supply and discharge hydraulic pressure before disconnecting any hydraulic fluid coupling.

Do not disconnect any hydraulic coupling without first shutting down the hydraulic power supply and discharging stored pressure to zero. Tie down or otherwise secure all pressurized hoses to prevent movement during system operation and to prevent the hose from whipping about in the event of a rupture.

Hazard - Shut off the supply of compressed gas and discharge residual gas pressure before you disconnect any compressed gas coupling.

Do not release gas connections without first disconnecting the gas supply and dis-charging any residual gas pressure to zero.

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Preliminary Pages M18-16254-EN

Warnings

Explosion Hazard - Wear eye protection and use protective shields or screens whenever any possibility exists of a hazard from the failure of a specimen, assembly, or structure under test.

Wear eye protection and use protective shields or screens whenever a risk of injury to operators and observers exists from the failure of a test specimen, assembly, or struc-ture, particularly where explosive disintegration may occur. Due to the wide range of specimen materials, assemblies, or structures that may be tested, any hazard resulting from the failure of a test specimen, assembly, or structure is entirely the responsibility of the owner and user of the equipment.

Hazard - Ensure components of the load string are correctly preloaded to minimize the risk of fatigue failure.

Dynamic systems, especially where load reversals through zero are occurring, are at risk of fatigue cracks developing if components of the load string are not correctly preloaded to one another. Apply the specified torque to all load string fasteners and the correct setting to wedge washers or spiral washers. Visually inspect highly stressed components such as grips and threaded adapters prior to every fatigue test for signs of wear or fatigue damage.

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Preliminary Pages

Table of Contents

1

Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Connecting and Configuring Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Expression Builder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Test Profiler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

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Chapter 2 Connecting and Configuring Transducers . . . . . . . . . . . . . . . . . . . . . . 2-1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Transducer Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Self Identifying Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3User Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3High Level DC Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Low Level AC Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Connecting User Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Simple Connection of a High Level DC Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Additional Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6Configuring the Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7Calibrating User Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Connecting Low Level AC Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11Connecting the Wheatstone Bridge to Controller . . . . . . . . . . . . . . . . . 2-14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14Configuring the Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15Calibrating User Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

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Chapter 3 Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

What is a Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

viiProduct Support: www.instron.com

Preliminary Pages

Physical Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Virtual Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Corrected Extension Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Availability of Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Creating Physical Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Associated parameters of a Physical Measurement. . . . . . . . . . . . . . . . . . . . . 3-5

Pretest Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Rate Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Creating Virtual Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Creating an Expression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Creating a Corrected Extension Measurement. . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Creating a Compliance Data File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9Creating a Corrected Extension Measurement . . . . . . . . . . . . . . . . . . . 3-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

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Chapter 4 Expression Builder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

What is the Expression Builder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1Creating Virtual Measurements with the Expression Builder . . . . . . . . . . . . . . 4-2Creating a User Calculation with the Expression Builder . . . . . . . . . . . . . . . . . 4-5Identifying a Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

What is a Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8Adding A Domain to a Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

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Chapter 5 Test Profiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Test Profiler Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Enhanced Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2User Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Using the Test Profiler Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Test Profile Menu and Tool bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4Test Profiler Tabs (Screens) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

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Preliminary Pages

Block Parameters Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6Block Control Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7Test Description Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7Display Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7Unit Conversion Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

Creating Waveform / Profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9Initial Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

What do I want the test to do?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9What information do I want to get out of the test?. . . . . . . . . . . . . . . . . 5-10

Creating a Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10Block Parameters Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11Setting the Control Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12Tensile/Compressive Extension and Strain . . . . . . . . . . . . . . . . . . . . . . 5-13Selecting Block Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14Triangle waveform. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14Relative Ramp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15Absolute Ramps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16Hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17Segment Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18Name. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

Block Control Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18Test Description Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19Display Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

Selecting Calculations and Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20Use of User Calculations with Test Profiler . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20Creating a User-Calculation for Hysteresis Energy . . . . . . . . . . . . . . . . . . . . 5-21

Test Profiler Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26Testing System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26Profiler Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26Repetition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27Time Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27

ixProduct Support: www.instron.com

Preliminary Pages

Ramps, Waveforms and Holds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27

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Chapter 1

Introduction

Important Information About This Manual

This manual is relevant to the Bluehill 3® running on the following testing sys-tems:

• 5900 Systems

• 5500A Systems

• 5500 Systems

• DX Systems

• KN Systems

• LX Systems

• RD Testing Systems

• SF Systems

It is important to understand that the above testing frames all provide a standard controller and conditioner card configuration that enable the connection of trans-ducers in a more simplified process than earlier testing systems.

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Overview

Instron’s Bluehill 3® software was developed to run on an array of Instron testing instruments. This manual was developed to provide a more detailed explanation of the advanced features of the software. Each chapter within the manual addresses separate topics and can be reviewed individually of grouped to cover the necessary topics. Topics covered in this manual include:

• Connecting and Configuring Transducers

• Measurements

• Expression Builder

• Test Profiler

As it is not possible to discuss each users need the manual will provide a detailed overview of the capabilities of the testing system with using general examples of how each section can be applied to the users need.

Connecting and Configuring Transducers

Standard testing systems provide the user with transducers that measure exten-sion, force and as an option strain. Many users have the need to connect additional transducers that in the past were difficult to configure. The 5900 testing system and Bluehill software streamlined this process. Your software now has the ability to configure most any transducer including selecting units, defining limits and cal-ibrating the device. This chapter will demonstrate how to connect and configure these devices as well as explaining the options that a user must consider when determining how to connect the transducer.

Measurements

Within the Bluehill 3 application measurements provide data that is available for test control, graphing and analysis. A Physical Measurement is data from a transducer that is connected to the testing system and a Virtual Measure-ment provides data that is calculated using a mathematical expression. This manual will further explain these measurements and show you how to cre-ate measurements.

Expression Builder

The Expression Builder is a tool that enables the user to create custom calcula-tions, virtual measurements and logical expressions that can evaluate specific val-ues. It is Integrated into the software to calculate the value of any expression,

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provided the formula is comprised of predefined values and follows standard alge-

braic rules. The user can then utilize this function to calculate results, define test rates or identify a domain in which a calculation is to be performed.

Test Profiler

Test Profiler is a general purpose cyclic and block testing program that is fully integrated into the Bluehill 3® testing software. Test Profiler shares many of the functional features with the standard Bluehill 3® testing types, making it much easier to use, and requires that you are using the Bluehill software with either the Tension or Compression test type installed.

The Test Profiler is not compatible with Flexure or PTF. These programs can co-exist with the Test Profiler application but do not interact with Test Profiler Meth-ods.

If you have questions about the information in this manual or your testing system you can contact your local Instron Representative.

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Chapter 2Connecting and Configuring

Transducers

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Introduction

Transducers are sensors that convert energy into an electrical signal that can be input into your mechanical testing system. A standard electro-mechanical testing system has two transducers, one that measures how far the crosshead has moved and one that measures the forces exerted on a specimen. The movement of the crosshead is measured by an optical encoder mounted to the motor within the test-ing frame. Force is measured by a load cell, typically this load cell is a strain gauge device connected to the crosshead and plugged into a Signal Conditioner Module (SCM) in the frame controller. The testing system uses these transducers to aid in the characterization of materials. Through the software controlling the frame values for force, elongation, stress and strain can be derived.

When the need to connect additional transducers arises the user can add up to three additional SCM’s to the controller, each transducer requires a dedicated SCM. The SCM provides an interface to the transducer through a 25 pin “D” con-nector that extends through the face of the controller. These boards are optional and are not provided unless specified by the customer. If the user has a need to connect more that four transducers to the testing system the Channel Expansion Module (CEM) option gives the user the ability to connect four or eight additional transducers.

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Transducer Types

When connecting transducers to the 5900 testing system they are classified in one of three categories; Load, Strain or User-Defined. If your transducer was pur-chased as part of the testing system, an Instron transducer, it is also classified as a Self Identifying. When connected, the controller reads a resistive network within the connector that identifies the transducer type and capacity. These transducers have also been rationalized to enable to user to perform an automatic electrical calibration. User Transducers are initially Non-Self Identifying, they are not auto-matically recognized by the controller. During the set up of the User Transducer the operator “teaches” the testing system to recognize the device.

Self Identifying Transducers

The standard Instron transducers have a connector that contains a “Cal and ID” board. This board provides the resources to identify the transducer as to its type, whether its a load cell or extensometer, its capacity and provides the necessary electronic components to enable to user to calibrate the transducer automatically.

User Transducers

The user transducer must be connected to the system and configured in order for the testing system to recognize, calibrate and use the device for testing. The 5900 controller further classifies user transducers into two categories, High Level Direct Current (DC) or Low Level Alternating Current (AC). This classification is based upon the output signal of the transducer itself. As part of the process of con-figuring the transducer connector the user must identify the transducer category. Additional considerations that the user must take into consideration are:

Does the transducer require excitation - Some devices require an external voltage applied to the transducer for it to operate.

Do the transducer outputs require conditioning - Devices such as strain gauges require conditioning electronics in order to create a signal that is linear and of sufficient amplitude.

How will the device be calibrated. - During the configuration of the trans-ducer the user must perform a calibration to enable the SCM to quatify its out-put. Typically this requires the transducer to output a “zero signal” and a “full scale” signal. The operator must have some means to vary the output voltage of the transducer to perform this function.

High Level DC Devices

High level DC devices will output a signal between 0.06 VDC and 10 VDC pro-portional to the magnitude of the measurement being monitored. Maximum volt-age is 12 VDC, voltages above that level may cause damage to the SCM. Maximum input impedance is 10K Ohms.

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Low Level AC Devices

Typically these types of transducers are a full wheatstone bridge. They require an excitation to operated and have a low level of sensitivity, typically a few millivolts per Volt. They also provide no ability to perform a calibration. Because of this it becomes a very difficult transducer to work with. Users that need to have the out-put of a bridge or single strain gauge will usually use some form of bridge com-pletion circuit and condition box that provides a high level DC output to the 5900 test system.

Connecting User Transducers

On the 5900 Testing system all transducers plug into the controller located on the left side of the test frame. An option, this requires the installation of an additional SCM into the controller. The controller can have up to 12 SCM’s connected, 4 in the controller itself and up to 8 additional SCM’s in the CEM. Refer to the dia-grams below for slot designations and compatibility.

Table 2-1.

CONNECTOR LABEL

TRANSDUCER CONFIGURATION SOFTWARE LABEL

Load Load Cells only 1 labeled as Load

Strain 2 Strain 2

Load 2

LVDT 2

2 labeled as Strain 2

Strain 1 Strain 1

Load 3

LVDT1

3 labeled as Strain 1

I/O If I/O card fitted - no trans-ducers can be connected

If SCM Fitted:

4 labeled as I/O

LoadLoad

I/O Strain 1

Strain 2

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* These are only available if CEM, shown below, is fitted to the Expansion slot between the Strain 1 and Strain 2 connectors. Also note, only load cells can be connected to the load SCM.

5* 5

6* 6

7* 7

8* 8

9* 9

10* 10

11* 11

12* 12

Table 2-1.

CONNECTOR LABEL

TRANSDUCER CONFIGURATION SOFTWARE LABEL

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Simple Connection of a High Level DC Device

This is the most straight forward way of connecting transducers, it requires a 25 Way D-type plug and two wire links. The wire links are used to identify

Transducer is a high level DC device (pin 21 to pin 23)

The device is a User Transducer with a Rcode of “0,0” (pin 4 to pin 5)

The user then connects the transducer “+” and “-” leads to the connector as shown below (“+” to pin 19 “-” to pin 18).

The transducer may need an external conditioning box to enable the device to be calibrated. During the calibration of the transducer the user must be able to gener-ate specific output signals in order for the SCM to condition the electronics to rec-ognize these signals as a specific value. With these connections made the transducer can now be connected to the SCM in the controller.

Additional Considerations

In the above example an Rcode of 0,0 was used. If more than one User Transducer will be connected to the testing system the user must assign a unique Rcode to each transducer. This is required even if the two transducers are not being used at the same time. During the calibration process the testing system will store the calibra-tion coefficients associated with the transducer, this information is stored based upon the identification of the transducer. If it is necessary to connect multiple user transducers contact your Instron Service Engineer who can provide the additional components and services required to uniquely identify each transducer.

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Configuring the Software

New transducers must be configured in the Admin section of the Bluehill 3 soft-ware, this will enable the transducer to be used within a test method. Transducers are added to the system in the Admin area of the software. Once in the Admin area, select Configuration > Transducers.

The operator can select User-defined in the available transducer type listing and click on the right triangle to add a new transducer to the Transducer listing. Once added the transducer will become available to configure as shown below.

The user can now uniquely identify the transducer, operating units, its physical connection and how it is to be identified. In this example we will be configuring a temperature chamber with the testing system enabling the user to record the cham-

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ber temperature during a test. We will Change the name of the transducer from User-defined 12 to “Temperature Chamber”

Set the units to “Temperature”

Indicate the chamber will be connected to “3 labeled as Strain 1”

Identify the chamber using “Resistor Codes”

Once the user selects the “Resistor Codes” option an additional field will be dis-played with a pre-filled value of “0,0”. The user can read the correct resistor code from the connector by clicking on the “Find” button to the right of the field.

Additional options available to the user to further define the transducer are:

Require Verification - Verification is the comparison of the transducer to a national or international standard. To ensure that the verification for the selected transducer is valid, select Require verification and enter the date that the current verification expires. When the transducer is selected for a mea-surement in a test method, the system verifies that the date is valid. If the date has expired, the system does not start the test. The system will displays a warning in the system event log in the console area 30 days prior to this expi-ration date so that you can schedule a service appointment before the verifica-tion expires.Once the verification date passes, the system cannot start tests that use this transducer until the verification date is updated.

Override Default Transducer Settings - If your testing system has both upper and lower test spaces it may require customizing a transducer's settings so the device functions properly in a given test space. These settings are available for both the upper and lower test space for each transducer. This setting reverses the polarity of a transducer's measure-ment in the Bluehill® software. This affects the polarity of any soft-ware inputs such as test rates and end levels and also the polarity of the live display for the measurement. Refer to the Bluehill Help system for additional details.

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Once configuration of the transducer is complete the software must be re-started. Upon re-starting the software a new transducer icon, User Transducer 1, will be displayed in the console section of the software. The transducer can now be cali-brates for usage.

Calibrating User Transducers

Calibration ensures that the output voltage from a transducer is directly propor-tional to the force exerted on the transducer. In other words, it ensures that the transducer measures correctly. There are two types of calibration: manual and automatic, the default calibration for user transducers is manual. Calibration is required when a transducer is first installed, and recommended at regular intervals after installation. Between calibrations, you can balance the transducer to ensure that the zero point of the transducer remains stable. Clicking on the user trans-ducer icon will open the calibration dialog box as shown below.

The first step is to select the Transducer, the default setting for all user transducers is an LVDT. Clicking on the drop down list for the transducer will display the available user-defined transducers. Selecting the Tem-perature Chamber will change the system of units for all of the calibration fields to temperature. The user needs to define the calibration settings as follows:

Full Scale - Enter the full scale value of the transducer. In this example the full scale value is 1000 degrees C.

Calibration Type - Only manual calibration is valid for user transducers

Calibration Point - The user must identify a value for the calibration point, this value must be at least 10% of the full scale value. During the calibration process the transducer will have to be set to this value to successfully cali-brate. If the device does not give the user the ability to output a preselected

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value the use must incorporate an external conditioning box that will provide this capability.

Offset - This is the lowest value in the scale of the transducer, it is the point at which the transducer outputs 0 VDC. In this example we will use -1000 C.

Proportional Gain - Do not change this value, during the calibration process the SCM firmware will determine the gain value based upon the input signals it receives.

Once these values have been entered in the dialog box the user can calibrate the transducer as follows:

1. Click on the “Calibrate Button” in the dialog box, an additional dialog box will open directing the operator to set the transducer to the offset point to per-form a balance.

2. The user must set the transducer to the point at which it output is 0 VDC, then click OK. The controller will now balance the output of the transducer with the SCM electronics.

3. Once complete the software will direct the user to set the transducer to the Calibration Point

4. The user must now set the transducer to the calibration point value entered in the dialog box. Once the transducer is stable at the calibration point click OK. The system will now conduct a span adjustment where it correlates the output voltage of the transducer to the calibration point value. From this adjustment the system can create a relationship between the transducer output voltage and the values it is meant to represent. Upon completion of the span adjustment the user will be directed to return the transducer to the offset point. Return the transducer to the offset point and click OK.

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5. Upon completion of the fine balance operation the transducer is calibrated and the calibration dialog box will displayed as shown below.

With the calibration process complete, the dialog box will indicate a status of cali-brated and the date and time the device was calibrated. The User transducer Icon in the console will now display the icon in color indicating that it is calibrated.

This completes the process of adding a user transducer, this device can now be added as a measurement within any test method. If you disconnect the transducer you must remember that it is designated for use in Slot 3 of the controller, if you plug this device in any other slot the system will not recognize the device or col-lect any data from it.

Connecting Low Level AC Device

Low level AC devices are typically strain gauges, used in a Wheatstone bridge that provide a highly accurate means of measuring strain on a specimen. The com-plete Wheatstone bridge contains four active gauges, as shown below:

The bridge requires an excitation voltage to operate and in an unstressed state the output of the bridge would be equal to zero. If any of the active gauges change their values the resulting measured output will change, that change represents the strain on the specimen. More commonly users will be connecting a single active gauge to measure strain referred to as a quarter bridge.

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Using a single gauge required the use of a bridge completion circuit as the 5900 will only accept the connection of a full bridge. As shown in the previous diagram R1, R2 and R3 would form this bridge completion circuit and when connected to the strain gauge would provide a complete bridge to the SCM. One additional consideration the user must include is the ability to perform an electrical calibra-tion. The 5900 and Bluehill 3 must be able to recognize the output of the circuit as

a specific value of micro-strain. The calibration process goes through a sequence of steps the “teach” the SCM how to recognize these inputs and relate them to spe-cific values of micro-strain. To do this the user must provide some means to force the bridge to output a change in the balance of the bridge.

As shown in the previous diagram a calibration resistor (Rcal) and a switch (S1) are added to the circuit to provide for this calibration. The calibration resistor pro-vides a means to create an imbalance in the bridge when the switch is closed. The value of the resistor can be calculated but require that the user have a complete understanding of the components that make up the bridge circuit.

Strain gauges used in materials testing are usually 120 or 350 Ohm gauges, for simplification of this explanation the following criteria will be used:

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1. A 350 Ohm strain gauge will be used (Rgauge)

2. The gauge factor (F) is 2.105

3. Full scale of the gauge is 2000 micro-strain (ε)

4. The calibration point is 2000 micro-strain

5. To calculate the value of the calibration resistor you must first calculate how much of a change in resistance must be generated in the bridge to simulate the calibration point. This is done as follows:

RΔ = ε * (F * Rgauge)

OR

RΔ = .002 * (2.105 * 350)

RΔ = 1.4735 Ohms

6. With the necessary change in resistance now known calculate the Value of the calibration resistor as follows:

Rcal = [ Rgauge * (Rgauge - RΔ )] / [ (Rgauge - (Rgauge - RΔ )]

OR

Rcal = [350 * (350 - 1.4735)] / [350 - (350 - 1.4735)]

Rcal = (350 * 348.5265) / (350 - 348.5265)

Rcal = 121984.27 / 1.4735

Rcal = 82785.388 Ohms (82.785K Ohms)

7. Finding a precision resistor with the value calculated is not always possible. Once you know the value of of resistance needed use a resister as close as possible to the calculated value. In this example we will use a resistor of 90.9K Ohms. You cannot use a resistor that has a lower value of resistance than calculated, this would create a value higher than the full scale value.

8. Using a 90.9K Ohm resistor we need to now calculate the resistance in paral-lel (Rt)when we close S1 to unbalance the bridge.

Rt = ( Rgauge * Rcal ) / ( Rgauge + Rcal )

OR

Rt = (350 * 90.9K) / (350 + 90.9K)

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Rt = 31815000 / 91250

Rt = 348.65753

9. Using a 90.9K Ohm calibration resistor we can now calculate the exact micro-strain value for the calibration point as follows:

ε = (Rgauge - Rt) / ( F * Rgauge )

OR

ε = (350 - 348.65753) / ( 2.105 * 350 )

ε = (1.34247) / ( 736.75 )

ε = 0.0018221 = 1822.1με

Connecting the Wheatstone Bridge to Controller

As with the High DC device explained earlier this connection requires a 25 Way D-type plug and one wire link. The wire link is used to identify:

The device is a User Transducer with a Rcode of “0,0” (pin 4 to pin 5)

The user then connects the bridge leads to the connector on pins 14 and 15 and the excitation to pins 1 and 2 as shown below.

.

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Configuring the Software

New transducers must be configured in the Admin section of the Bluehill 3 soft-ware, this will enable the transducer to be used within a test method. Transducers are added to the system in the Admin area of the software. Once in the Admin

area, select Configuration > Transducers.

The operator can select User-defined in the available transducer type listing and click on the right triangle to add a new transducer to the Transducer listing. Once added the transducer will become available to configure as shown below.

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The user can now uniquely identify the transducer, operating units, its physical connection and how it is to be identified. In this example we will be configuring the Wheatstone Bridge with the testing system enabling the user to record the the

strain measured by the strain gauge during a test. We will Change the name of the transducer from User-defined 12 to “Wheatstone Bridge”

Set the units to “Strain”

Indicate the bridge will be connected to “3 labeled as Strain 1”

Identify the chamber using “Resistor Codes”

Once the user selects the “Resistor Codes” option an additional field will be dis-played with a pre-filled value of “0,0”. The user can read the correct resistor code from the connector by clicking on the “Find” button to the right of the field.

Additional options available to the user to further define the transducer are:

Require Verification - Verification is the comparison of the transducer to a national or international standard. To ensure that the verification for the selected transducer is valid, select Require verification and enter the date that the current verification expires. When the transducer is selected for a mea-surement in a test method, the system verifies that the date is valid. If the date has expired, the system does not start the test. The system will displays a warning in the system event log in the console area 30 days prior to this expi-ration date so that you can schedule a service appointment before the verifica-tion expires.Once the verification date passes, the system cannot start tests that use this transducer until the verification date is updated.

Override Default Transducer Settings - If your testing system has both upper and lower test spaces it may require customizing a transducer's settings so the device functions properly in a given test space. These settings are available for both the upper and lower test space for each transducer. This setting reverses the polarity of a transducer's measure-

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ment in the Bluehill® software. This affects the polarity of any soft-ware inputs such as test rates and end levels and also the polarity of the live display for the measurement. Refer to the Bluehill Help system for additional details.

Once configuration of the transducer is complete the software must be re-started. Upon re-starting the software a new transducer icon, User Transducer 1, will be displayed in the console section of the software. The transducer can now be cali-brates for usage.

Calibrating User Transducers

Calibration ensures that the output voltage from a transducer is directly propor-tional to the force exerted on the transducer. In other words, it ensures that the transducer measures correctly. There are two types of calibration: manual and automatic, the default calibration for user transducers is manual. Calibration is required when a transducer is first installed, and recommended at regular intervals after installation. Between calibrations, you can balance the transducer to ensure that the zero point of the transducer remains stable. Clicking on the user trans-ducer icon will open the calibration dialog box as shown below.

The first step is to select the Transducer, the default setting for all user transducers is an LVDT. Clicking on the drop down list for the transducer will display the available user-defined transducers. Selecting the Wheatstone Bridge will change the system of units for all of the calibration fields to strain. The user needs to define the calibration settings as follows:

Full Scale - 2000 με, as defined earlier in this section

Calibration Type - Only manual calibration is valid for user transducers

Calibration Point - This is the cal point that was calculated earlier in this sec-tion (1822.1με)

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Offset - 0.00.

Proportional Gain - Do not change this value, during the calibration process the SCM firmware will determine the gain value based upon the input signals it receives.

Once these values have been entered in the dialog box the user can calibrate the transducer as follows:

1. Click on the “Calibrate Button” in the dialog box, an additional dialog box will open directing the operator to set the transducer to the offset point to per-form a balance.

2. The user must set the bridge in an unstress state where the bridge is balanced and there is not output, then click OK. The controller will now balance the output of the transducer with the SCM electronics.

3. Once complete the software will direct the user to set the transducer to the Calibration Point

4. At this point, using our example the user would close S1 placing the calibra-tion resistor in parallel to R3 this would cause the bridge to output a voltage that represents the calibration point of 1822.1 με. Once the transducer is stable at the calibration point click OK. The system will now conduct a span adjust-ment where it correlates the output voltage of the transducer to the calibration point value. From this adjustment the system can create a relationship between the transducer output voltage and the values it is meant to represent. Upon completion of the span adjustment the user will be directed to return the transducer to the offset point. Return the transducer to the offset point and click OK.

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5. Upon completion of the fine balance operation the transducer is calibrated and the calibration dialog box will displayed as shown below.

With the calibration process complete, the dialog box will indicate a status of cali-brated and the date and time the device was calibrated. The User transducer Icon in the console will now display the icon in color indicating that it is calibrated.

This completes the process of adding a low level AC user transducer, this device can now be added as a measurement within any test method. If you disconnect the transducer you must remember that it is designated for use in Slot 3 of the control-ler, if you plug this device in any other slot the system will not recognize the device or collect any data from it.

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Chapter 3Measurements

What is a Measurement

A measurement is a value which represents a magnitude. For example, in material testing the amount a specimen is elongated during a tension test is a measurement referred to as elongation and refers to the amount the specimen has stretched. This elongation value can then be put into a mathematical formula (Δ gauge length / original gauge length) to calculate the strain of the material at any given point dur-ing a test.

In the previous example we have defined the two types of measurements that exist within the Bluehill 3® software. The measurement of the of how much the speci-men has been elongated is taken from the movement of the crosshead in the test-ing system and is considered a Physical Measurement. The measurement of the strain of the specimen is calculated based upon the the original length of the spec-imen and its change in length. This type of measurement is referred to as a Virtual measurement within the software.

Physical Measurements

Physical measurements provide data directly from transducers connected to the testing system. When a new method is created the software automatically pro-vides the following physical transducers within the method:

• Time

• Extension (Electromechanical systems)

• Load

• Strain 1 (if connected)

• Strain 2 (if connected)

Physical measurement are defined within the test method, this enables each test method to have a separate configuration of physical measurements. To accommo-date this ability each physical measurement must have a unique designator or name and specifically identify the transducer providing the data.

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Virtual Measurements

Virtual measurements provide data related to the specimen that has been calcu-lated from one or more physical measurements.For example, stress is derived from the load applied to the specimen divided by the cross sectional area of the specimen. When a new method is created the software provides several pre-defined virtual measurements:

• Tensile Extension (Compressive, Flexure, Peel)

• Compressive Load (Flexure)

• Tensile Strain (Compressive, Flexure)

• Tensile Stress (Compressive, Flexure)

• Load / Width

• Tenacity

As with physical measurements these measurements are uniquely defined within each test method. You can create additional virtual measurements within a test method by providing a unique name, a valid expression to calculate the measure-ment and the units of the measurement.

Corrected Extension Measurement

The corrected extension measurement provides data on the compliance, “elastic give”, of the testing system. It is important to understand that this measurement is a property of the entire load string not just the test frame. The load string consists of the frame, load cell, adapters and grips or fixtures. In order to correct for this compliance the user must first create a compliance data file, a file needs to be cre-ated for each different configuration of the load string and applied appropriately.

Availability of Measurements

Measurements created within a test method are available in several area of the method including calculations, test control, live displays, graphs, raw data viewer, and results. When you create a measurement, the system updates all these sections to make the new measurement available. If you have a sample open, the new mea-surement is available for all untested specimens.

If you remove a measurement from a test method, the system again updates all the above sections to remove the measurement as an option. If the measurement is in use, the system changes the display to show No selection made. For example, if you created a measurement called Load 2 and selected Load 2 to display in the live display section of console, then if it is removed from the method the live dis-play changes to show No selection made.

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If a measurement is modified, the system updates all the above sections to reflect the changes to the measurement. If you have a sample open, the modified mea-surement is available for all untested specimens.

The factors that affect the measurements available in the software are:

• the transducers connected to the system - the system detects the type of transducer and the connector it is plugged into to create a measurement for that transducer. For example, if a load transducer is connected to the Strain 1 con-nector on the frame, the system creates a new physical measurement named Load 2. If an extensometer is connected to the Strain 1 connector on the frame, the system creates a new physical measurement named Strain 1. You can edit any of these measurements to change the name.

• the selected test type - some measurements are specific to a test type. For example, compressive strain only appears in a compressive test method, peel extension is only available in a peel test friction test method.

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Creating Physical Measurements

Measurements are created within the test method they are to be used. As previ-ously indicated, physical measurements are created from transducers that a mea-suring the magnitude of a energy. This is not to be confused with connecting and configuring a transducer, in order to create a measurement the transducer must already exist within the software. In this section of the manual we will create a measurement of strain from an extensometer connected to the testing system.

1. Open or create the test method for the measurement to be added to and select the Measurements item in the Navigation Bar.

2. The extensometer does not need to be connected to the system to create the measurement but needs to be connected and calibrated in order to run a test using this test method.

3. Select “Strain” in the Physical Measurements list, by either double-clicking on the term Strain or clicking on the right pointing triangle. This will add the Measurement “Strain 1” to the select measurements list as shown below.

4. Once the measurement is added it can then be used within the test method.

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Associated parameters of a Physical Measurement

In addition to creating the physical measurement the user can identify the follow-ing additional parameters:

Pretest limits

Rate

Event

True strain control (strain measurements only)

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Pretest Limits

Pretest limits ensure that there are is residual or extraneous force on the specimen when the operator starts the test. The pretest limits define an acceptable range of under which the test may be started.

As shown above, when the pretest limits are enabled the operator can enter the

maximum and minimum values to establish an acceptable range. These values can be either positive or negative, and it does not matter if the maximum value is greater than or less than the minimum value. if the value at the start of the test is not within the specified range the system will prevent the start of the test and dis-play a message to the operator. The operator can then:

Re-install the specimen

Make other adjustments to the position of the crosshead.

Rate Measurements

If the user enables the Rate option the system will crate two separate data streams, one that measures strain and one that calculates the strain rate based upon the additional required parameters.

As shown in the previous diagram, when rate is enabled, additional fields are dis-play to specify how to calculate the rate. The default setting is 10 data points and the system calculates the rate using the difference between the current data point and the previous 10 points. As an example, the user adds a calculation for a Preset

Strain Rate = Strain @ point 114 - Strain @ point 104

Time @ point 114 - Time @ point 104

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Point of 16% Strain and ask for the strain rate. The system would calculate the rate as follows (for the purposes of this example 16% strain was data point 114):

Changing the number of data points to 20 would change the calculation as fol-lows:

The calculation of rate is a function of time. The user can identify that the rate be calculates using linear regression. if this option is enabled the software will per-form a linear regression over the number of data points identified.

Events

Events enable the user to specify an action to occur at a specific point during the test related to the measurement. Two separate functions can be triggered by the events item:

Playing of a wave (*.wav) file

Setting a digital output line

As shown in the previous diagram, the user can have the testing system play a wave file at a specific point in the test associated with the measurement by enter-ing a “Value” and a “Criteria”. A example is:

Criteria: “ Equals or passes through”

Value: 15 % (The value and units available are based on the measurement selected)

Once the Strain value reached 15% the system will play the selected wave file.

The second option in events requires the installation of the Analog Output and Digital Input / Output option in the 5900 frame. This option adds a circuit card to the controller that provides the user an interface for the connection devices. The analog output signals can be connected to control a device such as a chart record-ers or plotters. The Digital Input/Output provides 4 logic line inputs and 4 logic line outputs to trigger internal and external events.

When the event value and criteria have been met, you can configure the outputs, up to four, to:

Set

Reset

Strain Rate = Strain @ point 114 - Strain @ point 94

Time @ point 114 - Time @ point 94

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Retain

Available for Strain devices only is the check box “True Strain Control”. This gives the user the ability to identify the specific device to be used for true strain control during the test.

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Creating Virtual Measurements

As explained previously virtual measurements are calculated from a mathematical expression. This expression can use data from one or more physical measure-ments or it can use variables that the user inputs via the Numbered Inputs within the test method. Because of this virtual measurements provide the user with an unlimited number of possibilities when trying to define the measurement. As with physical measurements, the measurement must be created within the test method it will be used. In this section of the manual we will create a virtual measurement to calculate stress in an o-ring as required in ASTM D1414.

1. Open or create the test method for the measurement to be added to and select the Measurements item in the Navigation Bar.

2. Expanding the Virtual Measurements displays the two measurements that can be added; an expression or a corrected extension.

Expression: This option enables the user to use the Expression Builder to create custom equations.

Corrected Extension: This measurement corrects values of extension to allow for the compliance, or elastic "give", of the testing system.

Creating an Expression

As shown in the previous figure, selecting the expression option gives the user the ability to access the expression builder. the expression builder provides the user with the ability to create a customer equation. A detailed explanation in the use of the expression builder, including examples is covered in a later chapter in this manual.

Creating a Corrected Extension Measurement

In an effort to have measurement that are as accurate as possible the user must take into account the entire load string and the gripping of the specimen. Knowing how much compliance there is in the testing system will enable the user to correct the values of extension. This is done by conducting a test using a rigid specimen that deforms very little at the maximum test load. As load is applied to the speci-men, the system collects load and extension data. The extension data represents the amount of machine compliance corresponding to the respective load readings. The collected data is written to the data file, which is then used for correction while testing real specimens. It is important to understand that the machine com-pliance is a property of the entire testing system, not only the load frame. When you perform the test to create the compliance file you must use the exact same components in the load string as you will when running the tests, including the load cell, grips and couplings.

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Creating a Com-pliance Data File

Compliance data files are created by running a test, in this example we will utilize a tension type test.

1. Create a new tension test method and set the end of test criteria to a load value that is higher than the maximum load expected during the test or to the maximum capacity of the system. You must use the same load string components that will be used when testing specimens.

2. Set up the test to apply a small preload to ensure that there is no slack in the specimen.

3. Set up the end of test criteria as explained above and use stop as an end of test action

4. Set up the data logging so that a data point is collected for every 1% change in load.

5. Save the test method and return to the home screen.

6. Perform a test on the rigid specimen. The following diagram reflects the data collected during the test

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As you can see in the diagram, the total amount of compliance in the frame at 100N is slightly over 0.0016 inches. Viewing of the raw data from the test shows that 39 data points were collected and the extension at 100 Newtons to be 0.00162 inches.

7. Finish the test and save the data file, use a name that reflects the purpose and load string components (i.e. Compliance - 500 N Cell and Screw Grips). Doing this uniquely identifies the file and make it easier to search.

Creating a Corrected Extension Measurement

Once the compliance file has been generated the user can now create a corrected extension measurement.

1. From the measurements page expand the Virtual Measurements and add a corrected extension measurement.

2. The user must select the compliance file for the test method to use in calculat-ing the corrected extension.

3. Utilizing the Import button, select the compliance file to be applied when con-ducting tests with this test method.

4. Now, anytime testing is conducted with this test method, a corrected extension measurement will be made.

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Chapter 4Expression Builder

What is the Expression Builder

The Expression Builder is an integral part of the Bluehill 3 software that provides the user with the ability create virtual measurements, custom calculations, or logi-cal expressions. These expressions can be used to create a calculated data stream, test speeds or identify test end criteria without requiring custom software. It calcu-lates the value of any expression, provided the formula is comprised of predefined values and follows standard algebraic rules.

The expression builder can be displayed to the user in two different ways. When used to create a virtual measurement or to calculate a test rate the expression builder will be displayed as follows:

When used within the calculations section of a test method the expression builder will be displayed as shown below:

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You should notice that when used to create expressions for a caculation an addi-tional section is available that enables the user to identify a “Domain”. The domain provides the user the ability to define a specific region within the test curve. Identifying a domain enables the user to specify the test data that is available for a calculation or graph. Throughout the software, when available, the Expression Builder can be accessed by selecting its icon shown on the right.

When viewed, the Expression Builder window can be divided into five sections. they are:

The Expression window - This window will display your expression / equa-tion as you add values or terms to it.

The Variables window - This window will display the variable that can be used to create an expression / equation. Variables can be added to this listing by adding information to the test method such as:

Physical Measurements

Virtual Measurements

Sample / Specimen Numbered Inputs

The Unary Keys - These keys permit the user to select a single mathematical function to be performed, i.e. sin() will provide the sine of the value between the parentheses.

The Standard Calculator keys - These keys enable the user to enter numbers and basic mathematical functions into an equation. The ^ key represents expo-nential form, as in 4^2=16 and the E displays scientific notation as in 1E2 = 100.

The Domain Operators - Only displayed for the calculations, this section enables the user to identify the domain in which a calculation is to be per-formed.

Creating Virtual Measurements with the Expression Builder

As explained in the previous chapter, a measurement is a value that represents the magnitude of something. In this case we are going to create a measurement that calculates True Strain. True strain is defined by the American Society for Testing and Materials (ASTM) as the natural logarithm of the ratio of instantaneous gauge length to the original gage length and is expressed as follows:

E = ln (1+e)

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Where:

E = True Strain

ln = Natural Logarithm

e = Strain measurement

Before creating this measurement the user must first add the physical measure-ment for the extensometer (Strain 1) to be used. Once the physical measurement has been created you can now create the virtual measurement for True Strain. Selecting Measurements in the navigation bar will display the following screen.

From this screen the user expands the Virtual Measurements item in the measure-ment type window, selects the Expression item and clicks on the right facing arrow to add Expression 1 to the selected measurements listing as shown below.

The user can now create and name the expression to calculate true strain.

1. Change the Description field to title the expression “True Strain”

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2. Select the appropriate Unit Group for the measurement, in this case we will define this measurement within the Strain unit group. Once the Strain unit group is identified the software adds an additional field, “True Strain gauge length”

3. Because this is a virtual measurement, the software does not know the value to use for gauge length. We want the system to use the gauge length of the extensometer and can indicate this using the Expression Builder. select the Expression Builder icon to the right of the field.

We want the software to use the gauge length from the extensometer that has been defined as the physical measurement Strain 1. By expanding Strain in the Variables window you will see “Strain 1 gauge length”, double click on the term and it will be automatically entered into the expression window as shown below.

Click OK and the expression will be added to the virtual measurement field.

4. The user can now enter the equation for True Strain into the Expression field by selecting the equation builder icon to the right of the Expression field. This will open the expression builder in a new window, notice that the expression field is blank

5. Select the natural log unary key, this will add the function to the expression field as shown below with the words “Enter here” highlighted.

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6. Using the calculator keys select the number one and the minus sign, these will be added in order as shown below.

7. The last element of the equation is the value of strain measured by the extensometer. This can be found in the list of variables.

Expand the variable for physical measurements

Double click on the term Strain 1, this completes the equation and should be as displayed below.

8. You can validate the mathematical expression by selecting the “Validate” unary key. The software performs a validation of the syntax of the variables used and that the equation follows mathematical rules.

If the expression is valid the the software will display a small window stating “The expression is valid”. If the expression is invalid the software will display a window giving the operator an indication of the error.

Once the expression is validated the user can click OK to return to the virtual measurement screen where the creation of a virtual measurements using the expression builder is complete.

Creating a User Calculation with the Expression Builder

User calculations are built utilizing the expression builder. Once added to the Selected calculations list the user can access the expression builder by selecting the icon to the right of the user expression field as shown below.

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In this example, toughness will be calculated. Toughness is defined as the amount of energy per volume that a specimen can absorb before rupturing and is expressed as follows:

Jb/V

Where:

Jb = Energy in joules (at rupture/break)

V = Volume (Length * Width * Height)

We have identified that there are four variables within this calculation:

Energy @ Break

Specimen Length

Specimen Width

Specimen Thickness

With this information we can build our user calculation as follows:

1. Add a calculation for Break, in this example we will use the “Break (Stan-dard)” option.

2. Add a user calculation, these two calculations are shown below.

3. With the User calculation selected, select the expression builder icon to create the expression. With the expression builder open you can see that the Break calculation has been added to the list of variables. As long as a calculation has

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been added to the selected calculations list it will be available as a variable within the expression builder.

4. Expanding the Break calculation will display the available values that be cal-culated a the break point. Select the value Energy, this will calculate the energy to the break point, double-clicking on the term energy will add the value to the user expression window as shown below.

5. Continue to add the remaining portion of the mathematical expression as fol-lows

Add the “/” using the calculator keys

Add a left parentheses “(“

Expand the Specimen properties in the variables listing and add the term Length.

Add the “*” using the calculator keys

Expand the Specimen properties in the variables listing and add the term Width.

Add the “*” using the calculator keys

Expand the Specimen properties in the variables listing and add the term Thickness.

Add a right parentheses “)“

The user expression will display the following:

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6. The last step is to identify the units used to represent the result. In this case the units will be selected as Stress. The unit should follow the term or expression that it applies to, in this case at the end of the expression. Selecting the Units Unary key will display all of the systems of units available within the soft-ware. It is very important the the unit selected follows the values in the expression, in this case the expression results are in joules per volume. This can also be represented in lbs-in per in3, or lbs per in2. So we will select the unit pounds per square inch (PSI). This will result in the expression to be dis-played as shown below.

7. You can now either Click on the “Validate” unary key to perform the valida-tion of the equation or Click OK. By clicking OK the software will perform a validation prior to closing the expression builder window.

The user calculation will now be displayed in the “user expression” field on the calculation setup screen. This enables the result of the calculation to added to a Results table.

Identifying a Domain

What is a Domain

A domain is a region within the test curve. A new feature within Bluehill 3 enables the user to select the data that is analyzed for a calculation by identifying a domain for the calculation to be performed within. Users can utilize this func-tion to ensure that calculations are performed within specific areas of a test curve. As an example observe the test curve below.

Construction Line

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In this test curve the operator needed to calculate the modulus of the material and selected the “Automatic Modulus” calculation. Based upon the parameters the calculation uses, the modulus that was calculated and the construction line in the previous diagram indicates the region in which the calculation was performed. Modulus is a value that is calculated within the initial linear region of the curve. As shown in the previous diagram we can see that the calculation is not being per-formed within the initial linear region. This is because of the characteristics of the curve, there is no zero slope and the peak load is at the end of the curve, which sat-isfies the parameters of the automatic modulus calculation.

Having the ability to identify the domain in which the calculation is to be per-formed enables the user to restrict the analysis of data to a specific region of the curve. In this case the user can restrict the calculation domain so that only data from the start of the test until the specimen reaches 30% strain is analyzed. This will ensure that the calculation is performed on the initial linear region of the curve, as indicated by the construction line, and would produce a curve as shown below.

Adding A Domain to a Calculation

Using the previous explanation as an example the user can identify a domain for the calculation to ensure that the calculation is performed within a specific region of the test curve. To do this the user must have the test method open to the calcula-tions - setup screen and have the “Automatic Modulus” calculation selected (high-lighted” as shown in the following diagram.

ConstructionLine

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You should notice that the Domain field is automatically selected to analyze “Ramp 1” UNTIL “End of Data” which means that the software default is to ana-lyze from the start of the test until the end of the test. When entering domain parameters this is the format that must be followed

“Starting Point” UNTIL “Ending Point”

To change the Domain:

1. Select the expression builder icon to the right of the Domain field which will launch the expression builder in a new window. You will notice that the Domain function keys are available within the window as shown below.

2. Highlight and delete the current entry in the Domain field at the top of the window. The user can now identify a new domain, in this example we will choose to start analyzing data at the first data point by clicking on the “Start of Data” key in the Domain Operator section of the window.

3. You must now insert the term “UNTIL” into the expression.

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4. The ending point in the example is a value of 30% strain. This is entered in the following format:

“Measurement” = “Value of the Measurement”

“Tensile Strain” = 30 _%

As tensile strain is a virtual measurement, expand the virtual measurements in the Variables window and double click on the term “Tensile strain”, this will add tensile strain to the expression following “UNTIL”

Click on the “=” key

Enter the value 30 using the calculation keys

Add the units in percentage by clicking on the Units key and selecting Per-centage in “%”

5. The Domain window should now look as indicated below.

6. You can now either Click on the “Validate” unary key to perform the valida-tion of the domain or Click OK. By clicking OK the software will perform a validation prior to closing the expression builder window.

Remember, anytime changes are made to the parameters of a test method that the test method must be saved. If you do not save the changes, when the method is closed all changes will be lost.

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Chapter 5

Test Profiler

Introduction

The Test Profiler application is a general purpose cyclic and block testing package for systems running Instron Bluehill software. this application enables the user to create a unique combination of cyclic, tension, compression and relaxation/creep functions not otherwise available in the Bluehill 3 software. The method follows a profile waveform that the user creates, The profile controls the test, results selec-tion and plotting of the test curves.

Test Profiler Structure

Test Profiler test methods differ from other Bluehill methods in two specific areas, Test Control and selecting Results. Instead of setting up the test control sequence directly from the test control window as with the standard tensile or compression test, you access a profile editor via the “Edit Profile” button. This button launches the profile editor, it is a fully graphical programmer that allows you to select ramps, holds, triangles, and to set end points for specific Blocks.

Test Profiler not only allows you to create a control sequence to run the test but also lets you select calculated results that are specific to any zone or segment that you are interested in. Within the calculation area Blocks are referred to as “Zones”. For example, if you want to know the strain of the material during the

Test Control

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unloading ramp of the fifth cycle in a sequence of ten cycles, you can configure the software to analyze that specific portion of the test curve.

There is an additional feature in Bluehill 3 software that allows the user to filter the data within the graph called “Domain”. This allows you to select which cycles and zones you want to display in the graphs. You can display the complete sequence or you can identify a domain within the test sequence. This is in addition to standard graphical zoom that’s available in Bluehill.

Graph filtering is especially useful if the test has a large number of cycles but you are only interested in seeing some of them (e.g. first and last). It is also very help-ful if you have cursor-selected points on certain cycles from the display. Graph filtering does not affect the data storage functions – data will still be available from all the cycles. You can change the graph filtering criteria at any time.

Enhanced Control

Test Profiler is compatible with the enhanced control options within the Bluehill 3 software. This enables the user to perform ramps, triangles and hold waveforms in LOAD, STRESS or STRAIN control. Without these enhanced control features Test Profiler allows ramps and triangle waveforms to be run in POSITION control only. However, HOLDS can be in Position, Load, Stress or Strain control.

User Calculations

User Calculations are especially relevant to Test Profiler, it gives the user greater flexibility in creating results that are characteristic of cyclic tests. For example, the User Calculations can be used with Test Profiler to find hysteresis energy, which is not available with the basic Bluehill applications. Similarly, you can get the ratio between two preset points on the loading and unloading parts of a cycle using User Calculations.

Results

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Using the Test Profiler Application

Test Profiler follows a user created waveform to run tests, the profile is unique to the test method and cannot be used by another test method. If you want to run a different waveform you must edit the profile of the currently selected test method and save it with a new file name or create a new test method. In all cases only one profile can be associated with a test method. Upon exiting the profile editor the software will prompt the user to save any changes. When you save the profile it becomes linked to the current test method. Remember, when you save the profile its like changing any parameter in the current method, you must also save the changes to the test method. To access the profile editor select the Test Control item in the Navigation bar. A window displays the description of the current pro-file providing the user filled in the field when the profile was saved.

Clicking the Edit Profile button will launch the Test Profiler software. When launched a new window will opened containing the profile editor as shown below.

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Test Profile Menu and Tool bar

An easy to use menu and tool bar are located at the top of the Test Profiler win-dow. The menu (pull-down) enables the user to perform command functions within the program (i.e. Save, Print, Exit...). The tool bar repeats many of the functions that are found within the menus and is shown below.

Following is a list of the tool bar options and they’re assigned function:

SAVE - Save the current profile to a disk and link to current test method. Same as FILE-SAVE in pull-down menu.

PRINT Prints the current Test Profile report. Same as FILE-PRINT in pull-down menu. The report contents include the following:

• date and time

• file name and path

• test description

• block parameters

• block control settings

Cut - Removes the contents of the active block, with all its settings, to the Windows clipboard. Same as EDIT-CUT in pull-down menu.

Copy - Copies of the contents of the active block, with all its settings, and places it in the Windows clipboard. Same as EDIT-COPY in pull-down menu.

Paste - Copies the contents of the block stored in the Windows clipboard, to the active profile block. Same as EDIT-PASTE in pull-down menu.

Delete - Removes the contents of the active block. When you delete a block, the system permanently removes it from the profile. Same as EDIT-DELETE in pull-down menu.

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Insert Block - Inserts a block in front of the active block. Same as EDIT-

INSERT in pull-down menu. After you insert a block, the waveform parameters default to the following:

• Mode: Derived Extension

• Shape: Triangle Waveform

Append Block - Adds a block at the end of the Test Profile sequence. Same as EDIT-APPEND in pull-down menu. When you add a block, the waveform parameters default to the following:

• Mode: Derived Extension

• Shape: Triangle Waveform

Triangle Waveform Button - Changes the active block shape to a trian-gle waveform.

Relative Ramp Button - Changes the active block shape to a relative ramp.

Absolute Ramp Button - Changes the active block shape to an absolute ramp.

Hold Ramp Button - Changes the active block shape to a hold.

Previous Block - Makes the previous block in the sequence the active block.

Next Block - Makes the next block in the sequence the active block.

Return to Bluehill - Returns you to the Bluehill method. If any changes were made to the profile, the system prompts you to save the profile before exiting the editor.

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Test Type Identifier - Indicates the type of Test Profile you are creating.

=Tension Profile = Compression Profile

Test Profiler Tabs (Screens)

The four tabs in lower portion of the Test Profiler window (below the waveform display), are for selecting test control and display options. Remember, each block in the profile is controlled independently. You select a block and then use the tabs to select the different parameters made available within the different tabs. Due to the independent control of each block additional consideration must be given to the transition between blocks.

Block Parameters Tab

This tab allows the user to set the test control parameters for the selected block, the selected block is surrounded by the dashes. Special attention needs to be applied to this tab as the specific parameter set differs for each waveform shape

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Block Control Tab

This tab is only functional for the last block in the waveform. It allows the user to repeat blocks and determine crosshead action at the end of the test sequence.

Test Description Tab

This tab is for use to enter a brief description of the test waveform. This descrip-tion is displayed in the Setup Control-Test window of the method as a indication of profile used in the current method

Display Tab

These controls only affect the display of the waveform and permit the operator to amplify the display for easier use. They have no control over the block parame-ters.

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Unit Conversion Tool

For convenience, a Units Conversion tool (similar to calculator) is available in the pro-file editor.

Use WINDOW VIEW UNITS in the pull-down menu to access this tool.

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Creating Waveform / Profile

Initial Considerations

When creating a new profile the two most important things to consider are:

• What do I want the test to do?

AND

• What information do I want to get out of the test?

These two thoughts are significant factors in determining how many blocks the test needs to be divided into. Remember that you can still perform any Pre-Load or Pre-Cycling in Merlin test control, which is not part of your profile. For the purposes of discussion in the remainder of this section the “Tension Test Profile Example” will be used. This profile is on each system and is part of the initial software installation.

What do I want the test to do?

The answer to this question will help to determine how many blocks need to be used in developing your profile. Each distinct event should be a separate block, analyzing the “Example” profile you can see that there are 5 distinct portions to this test.

• The initial loading to 2 Newtons

• Cycling the specimen between 0mm and 5mm of extension three times

• A ramp to 10mm of extension

• Holding the specimen at 10mm of extension for 10 seconds

• Ramping back to 0mm of extension

By selecting block 5 as the active block you can see in the Block Control Tab that the repetitions are enabled, this allows the test to loop back to block 2 and repeat blocks 2, 3, 4, and 5. Using the repetition feature allows you to reduce the number of blocks you need to create.

It is often better to first plot your test using a pencil and paper. This procedure will allow you to map out the waveform without concern to its associated parame-ters. When doing this indicate the starting and ending points for each block until you are satisfied that you have created your waveform completely.

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What information do I want to get out of the test?

In some instances the desired results will determine a need for additional blocks or the starting and ending points for an existing block. An example of this instance is when you are looking for the hysteresis energy result on the loading and unload-ing of a single cycle. It would be necessary for the starting and ending extension points for the cycle to be the same value. In this way the extension of each seg-ment within the cycle would be the same value.

Once you have determined the required waveform necessary to perform the test properly it is only a matter of selecting the available waveforms and entering the associated parameters.

Creating a Profile

One and only one profile is linked to and saved with the test method. To create a new profile, you open a test method and then click on the “Profiler...” button to open the Profiler editor. Use the editor to change the existing profile and save the changes when you exit the editor. At this point the new profiler is only linked to the current method. However, this link is not permanent until you re save the method. Use “Save As” to save the new profile to a new or different method, or “Save” to save the new profile in the current method.

In analyzing the “Example” waveform that is provided in the example test method, five distinct blocks were identified as necessary to perform to complete test.

Note: The Example waveform shown above is magnified to show details

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Adding additional blocks is done by selecting the Append or Insert from the menu

or tool bar. New blocks use the triangle shape and default parameters as shown in the following display.

To remove blocks, simply select Delete from menu or tool bar. The active block (the block surrounded with dashes) is removed from the waveform.

Block Parameters Tab

Having the appropriate number of blocks to conduct the test we must now address the parameters of each block. When entering the block parameters it must be remembered that changing the parameters only affect the active block - that block surrounded by dashes. Selecting block 1 as the active block and ensuring that the Block Parameters Tab is chosen displays the following:

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Block Parameters differ depending upon the Waveform Shape.

Setting the Control Mode

• The first selection that must be made is the control Mode. The availabil-ity of the control modes depends on the options installed in the testing system that will eventually perform the test. The Control Mode identifies the trans-ducer feedback signal that controls the system during each block. The Test Pro-filer supports the following control modes:

• Extension

• Strain 1

• Strain 2

• Load

• Axial Extension, either Tensile Extension or Compressive Extension

• Axial Strain, either Tensile Strain or Compressive Strain

• Stress, either Tensile Stress or Compressive Stress

The control mode you select constantly compares a command signal to a feedback signal from the transducer and corrects for any difference in the signals. For example, under Load control, the system commands a specific load from the crosshead. If the current load (feedback) is different to that commanded, the sys-tem generates an error signal to drive the crosshead in the direction necessary to achieve the requested load. The table on the following page details the control modes available and their requirements within Profiler.

Triangle

Relative Ramp

Absolute Ramp

Hold

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Note: The color of the waveform indicates the controlling transducer.

Note: * Tensile Strain source in the Test Control area of the Test Method determines the measurement used as the controlling transducer.

Tensile/Compressive Extension and Strain

If the control mode selection is Tensile Extension, Tensile Strain, Compressive Extension, or Compressive Strain the controlling transducer is dependent on the “Tensile Strain Source” setting in the current Test Method TEST CONTROL -STRAIN screen. If the test method specifies using extension as the tensile strain source the waveform will be green in color and virtual measurement will be derived by dividing the crosshead extension by the specimen gauge length. If Strain 1 is the strain source the virtual measurement will be derived from the extensometer measurement/gauge length and the waveform will be blue in color.

If “Balance Axial Strain” is checked in a block, the Tensile Extension, Tensile Strain, Compressive Extension, or Compressive Strain, Bluehill balances the mea-surement before executing that active block. This is very useful, for example,

Table 5-1.

MODE

PHYSICAL MEASUREMENT TRANSDUCER COLOR REQUIREMENTS

Extension Motor Encoder Green None

Strain 1 Strain 1 Blue Extensometer

Strain 1 Signal Conditioner Module (SCM)

Strain 2 Strain 2 Blue Extensometer

Strain 2 SCM

Tensile or Com-pressive Exten-sion

Motor Encoder*

Extensometer*

Green

Blue

None

Extensometer

Strain 1/2 SCM

Tensile or Com-pressive Strain

Motor Encoder*

Extensometer*

Green

Blue

None

Extensometer

Strain 1 / 2 SCM

Load Load Cell Red None

Tensile or Com-pressive Stress

Load Cell Red None

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when you want to control or measure a specific deformation/elongation after your specimen was fatigued or conditioned by the previous block.

Selecting Block Shape

There are four different waveform shapes available within Test Profiler. They are:

• Triangle

• Relative Ramp

• Absolute Ramp

• Hold

The selection of the waveform to be used is done in one of two ways, either select-ing the waveform icon in the menu bar or selecting the waveform from the pull-down list in block Shape as shown below

Triangle waveform

A triangle waveform has maximum and minimum peak values. The editor dis-plays up to five cycles. If you specify more than five cycles or if there are space restrictions because of the number of blocks, the waveform appears as a dotted line. Two segments comprise one cycle in a triangle waveform, one loading and one unloading. This waveform appears in the Test Profiler workspace as the fol-lowing image:

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The following parameters should be identified:

1 - Initial Waveform Direction - The direction of the first waveform ramp. Select Maximum to ramp to the peak. Select Minimum to ramp to the trough.

2 - Maximum - The peak value. The Maximum can be either a control mode specific end point, or a non-control mode end point such as extension, axial strain, time or stress and is defined by the units selected. Specify a non-con-trol mode value by selecting the appropriate units. For example, if tensile extension is the control mode, Newtons can be selected as the end point. The Maximum value must be greater than the Minimum value.

3 - Minimum - The trough value. The Minimum can be either a control mode specific end point, or a non-control mode end point such as extension, axial strain, time or stress. Specify a non-control mode value by selecting the appropriate units. For example, select mm (millimeters) units for the mini-mum peak to be an extension value. The Minimum value must be less than the Maximum value.

4 - Rate - The rate at which the waveform ramps to the either the Maximum or Minimum value per time unit. You can enter only positive values in the units of the block’s control mode.

5 - Cycles - The number of waveform cycles for the block. You can enter val-ues in increments of 0.5 cycles or larger.

Relative Ramp

A relative ramp moves the crosshead from its current position by the delta value relative to the value in the previous block. For example, if the crosshead position is at 11 mm, a delta value of 5mm ramps the crosshead to 16 mm. This ramp appears in the Test Profiler workspace as the following image:

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• The following parameters should be identified:

1 - Delta - The amount the crosshead moves relative to its position in the pre-vious block. Control of the ramp is specified by the unit’s selection for the delta value. You cannot enter a negative value in the Delta field. For a nega-tive relative ramp, enter a negative value in the Rate field.

2 - Relative Ramp Rate - The speed of the ramp in the units of the control mode. The sign, either positive or negative, for the relative ramp rate indicates the direction of the ramp. For example, a negative rate ramps downward.

Absolute Ramps

An absolute ramp moves the crosshead to a tensile/compressive extension you specify as an end point value. For example, if the crosshead tensile/compressive extension is at 11 mm, an endpoint of 5 mm moves the crosshead to a tensile/com-pressive extension of 5 mm. This ramp appears in the Test Profiler workspace as the following image:

The following parameters should be identified:

1 - Duration - The period it takes for the ramp to reach the endpoint value. This parameter is available when you select Duration as the Ramp setup. You can specify only endpoints in the block’s control mode.

2 - Rate - The rate at which the ramp reaches the endpoint value. This param-eter is available when you select Rate as the Ramp setup. You can specify endpoints of any of the control mode or time.

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3 - Endpoint - The value that the ramp reaches at the end of the block. an end

point can be either a specific value of the blocks control mode or a value of a non-control mode.

Six measurements are available for setting the Endpoint when the ramp is deter-mined by rate:

• Tensile extension

• Tensile load

• Tensile strain

• Tensile stress

• Time

• Tenacity

You choose one of them by choosing the units in the Endpoint unit’s list box.

Hold

A Hold maintains the crosshead in its current position, the endpoint from the pre-vious block, for the amount of time that you specify. A hold constitutes a single test segment and appears in the Test Profiler workspace as the following image:

The following parameters should be identified:

1 – Criteria:

• Duration - The time period of the hold. Select from hours, minutes, and seconds.

• Rate of Change – Rate of change of a dependant measurement

If you choose rate of change as the hold criteria two additional parameters are required: the control mode, and the specified rate. If the control mode for the block is Extension or Tensile Extension, the rate of change may be specified as either a Load or Tensile Stress value and the hold ends when the rate is reached. If the control mode for the block control is Load or Tensile Stress you may select a

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Tensile Extension, Tensile Strain, Extension, Strain1 or Strain 2 rate of change to end the hold.

Additionally, if you hit the F5 key on your keyboard the hold ends immediately and transitions to the next block in the sequence.

2 – Duration - Length of the hold in time units

Segment Reference

You can specify up to 87 segments in a Test Profile. A single ramp or hold is one segment, while a triangle waveform is comprised of two segments, a loading seg-ment and an unloading segment. For example, a Test Profile with two ramps, a hold and a triangle waveform has a total of five segments.

Name

The name of a specific block in the Test Profile. When you insert a block in a sequence, the default name is the shape of the block with a number that represents the block position in the sequence. For example if you insert a block after third block and select a triangle waveform, the default block name is Triangle 4. You can and should specify a custom name to each block by clicking in the Name field and typing a new name, this will make identification of blocks for calculation selection much easier.

Number

Displays the current block position number within the profile. This field is for use with the repetition feature and cannot be edited. This number is entered into the “Loop to Block” field in the Block Control tab to indicate the point (block) within the sequence where the next repetition starts.

Block Control Tab

The block control section has two parameters to identify, the End of Test Sequence and the Block Repetition Sequence as shown below.

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Remember that this block is only active for the last block in the test sequence.

The system performs the End of Test Sequence after completing the last block. However, if a test value reaches any test stop criteria established within the Blue-hill software the system stops the test without completing the remaining blocks.

The Block Repetition Sequence allows the user to repeat common blocks. The Loop to Block field indicates which block in the sequence you wish to start the repetition in. The Repetition field allows the selection of the number of times the sequence will be repeated. The repetition function will not function if your last test sequence is a triangle waveform. Additionally, you cannot specify the system to repeat a profile that has a triangle waveform as its only shape.

Test Description Tab

This tab contains the user description of the Test Profile. You define the contents by either typing a new description or editing an existing one. When you select or browse for a the Profile Test Method the Test Description of the profile appears in the preview window. It also appears in the TEST CONTROL - TEST window of the test method to identify the profile the current method executes.

Display Tab

These controls affect the display appearance, not the block parameter settings.

You may choose to magnify the waveform or change the vertical offset.

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Selecting Calculations and Results

Test Profiler not only allows you to create control sequences to run the test but also to produce results that are specific to any block or segment that you are inter-ested in. For example, if you want to know the modulus of the material during the unloading ramp of the fifth cycle in a sequence of ten cycles, you can do this eas-ily.

The key to understanding how results are obtained from Test Profiler is as fol-lows:

The selection of calculations is basically the same as for Tension, Compression, and Peel Tear Friction test methods. There is however an additional parameter available called “Domain” which that enables the user to identify unique segments within the test. This allows you to get results based on the time elapsed from the beginning of any test segment in any block (e.g. Load at 10 seconds after the start

of the loading ramp to 2 Newtons) as shown below.

In using this feature the user can identify the domain the software analyzes the block named “Load to 2N” and the measurement, “Domain Time” of 10 seconds. In doing this the user has identified a specific area of the test curve that is searched to find the result.

Use of User Calculations with Test Profiler

Bluehill User Calculations are extremely valuable in many testing applications. This Bluehill feature adds flexibility and permits you to create results not nor-mally available in Bluehill. An example of a calculation that is not included in the Bluehill is hysteresis energy result. However, you can create that calculation using

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the Bluehill User-Calculations. Additionally, if you want the ratio between two

pre-set points on the loading and unloading parts of a cycle you can do it with User-Calculations.

Creating a User-Calculation for Hysteresis Energy

Hysteresis can be calculated from a stress-strain curve, as shown in following dia-gram.

The Shaded area within the curves represents the hysteresis. Hysteresis is the dif-ference between the loading energy and the unloading energy, expressed as a per-centage of the loading energy. Energy values are determined by calculating the area under the test curve. To better understand this value in the Tension Test Pro-filer using User-Calculations it is best to first change the value of the X axis to represent time.

B

A

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This curve now makes it easier to relate to one complete cycle within the wave-form. You can now calculate the energy under the curve for the loading and unloading cycles in the following manner.

• Calculate Energy to point A

• Calculate Energy to point B

When viewed in the context of a complete test, the user needs to identify the spe-cific cycle to be analyzed. The waveform below shows a specimen that was cycled three times and each of the three cycles were repeated three times. these are termed as cycle and repetition as illustrated below.

Step 1: Creating measurements that enable the user to count the cycles and repeti-tions. The user needs to create two measurements, a cycle count and a repetition count as shown below. For more detail refer to chapter 4 of this manual, Measure-ments.

Repetition 0 Repetition 1 Repetition 2

Cycle

0 1 2

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Step 2: In this example the 1st cycle of repetition 0 will be analyzed. The user now

needs to calculate the energy under the curve for the loading and unloading por-tions of this complete cycle. This is done by selecting the calculation “Area Under Curve” and adding it to the selected calculations list as shown.

Step 3: Having selected the calculation, the user must now identify the “Domain” for the software to analyze. By selecting the Properties button to the right of the domain field the Expression Builder will be displayed. The Expression Builder enables the user to identify the Zone, Cycle and Repeti-tion to be analyzed as shown below.

As shown in the illustration above the user first defines the “Zone” to be analyzed, in this case the loading segment of the cycle block. This identifies the specific cycle and repetition; cycle 1, repetition 0. When the user clicks the OK button the expression builder will Validate the expression, if the expression is valid the user will be returned to the calculation setup page.

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Step 4: Returning to the calculation setup page the user identifies the remaining parameters:

• X-Axis - Measurement in the X Axis

• Y-Axis - Measurement in the Y Axis

• Start Type - When in the domain to start analyzing data

• End Type - When in the domain to stop analyzing data

The user repeats this process for the “Area Under Curve” of the unloading ramp. Once both calculations have been identified they can be used within a User Calcu-lation to define the percentage of energy loss. Hysteresis is calculated as follows:

The result is expressed as a percentage. To create this add the User Calculation to the selected calculations list. The following screen will be displayed.

Loading Energy - Unloading Energy

Loading Energy* 100

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Select the expression builder button on the right of the user expression field to dis-

play the expression builder. From this the user can create the expression to calcu-late this desired result as shown below.

This can now be selected in the Results table for the test.

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Warning

Test Profiler Restrictions

Consider the following restrictions when you create, edit, or run a Test Profiler file:

Make sure you set all crosshead travel limits before performing a test with a Test Profile. Unexpected crosshead movement can cause personal injury and equipment damage.

Although the system warns you of any test that may exceed the perfor-mance envelope of the testing system, it does not restrict a Test Profiler from performing the test unless a transducer defined for control is not con-nected or calibrated.

Testing System

• The ballscrews of some older testing systems were not designed for through-zero load cyclic testing. These systems may display a nonlinear bump at the zero load point.

• Check that the testing system that will be performing the test profile is capable of achieving the parameters you set. The Profiler does not limit the parameter values you specify.

Profiler Display

• The system displays up to five cycles. If you specify more than five cycles or if there are space restrictions because of the number of blocks, the waveform appears as a dotted line.

• For more precision, enter the value in the Delta field rather than clicking and dragging the ramp.

Repetition

• The repetition parameters are available only when the last block in the sequence is active in the editor.

• The system performs the End of Test Sequence after completing the last block. However, if a test value reaches a Test Stop Criterion (e.g. specimen break), the system stops the test without completing the remaining blocks.

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• You cannot define a repetition sequence if the last block in the sequence

has a triangle waveform. Also, you cannot specify the system to repeat a test profile that has a triangle waveform as its only shape

Report

• The report details the following information: date and time, file name and path, test description, block parameters, and block control settings.

Blocks

• You can insert up to 87 segments when running on a 5900 Load Frame.

• There must be at least one block in a Test Profile. You cannot delete the last block in the workspace.

• You must first copy or cut a block to the Windows clipboard before you can paste the block. The block you paste has the same parameters as the block you copied or cut. You can only copy one block at a time and each time you copy a block, the system replaces any information in the clipboard with that block.

• Appending a block adds a block to the end of the Test Profile. The block's default parameters are the following:

• Shape: Triangle

• Control Mode: Tensile Extension.

• When you click on a block, it becomes active. The Block Parameters tab and the control mode icons reflect the settings of the active block.

• Deleting a block permanently removes it from the Test Profile.

Time Parameters

• The time unit’s selection determines the size of the Duration or Rate units. For example, if the control mode is Load and you select seconds, the rate is kN/sec.

Ramps, Waveforms and Holds

• The endpoint of the previous block determines the Hold value.

• You cannot enter a negative delta value. For a negative relative ramp, enter a negative relative ramp rate.

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• The sign, either positive or negative, for the relative ramp rate indicates the direction of the ramp. For example, a negative rate ramps downward.

• The endpoint units determine the measurement of the endpoint value as follows:

• Tensile extension

• Tensile load

• Tensile strain

• Tensile stress

• Tenacity

• Time

• You choose one of the measurements by choosing the units in the End-point unit’s list box.

• The combination of Cycle, Maximum, Minimum, and Initial Waveform settings can create various transitions between blocks.

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