I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 1

ME F342/ME C382: COMPUTER AIDED DESIGN

Dr. Regalla Srinivasa Prakash

Professor

Department of Mechanical Engineering

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 2

OBJECTIVES OF THE COURSE

CAD software and CAD hardware.

Mathematical modeling of parametric curves, surfaces and solids,and their computer simulation on

spreadsheets and using specialized solid modeling

packages.

CAD/CAM data exchange.

Introduction to finite element analysis and FEM practice on a specialized CAE package.

Rapid prototyping.

Students will be required to do several assignments and one CAD project.

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 3

EVALUATION SCHEME

Component

%Weightage

(Marks)

(Total

Marks=200)

Date Type

Test - 1 20% (40marks) 24/02/2014 (8-9

AM) CB

Test - 2 20% (40marks) 28/03/2014 (8-9

AM) OB

Practicals using

COMSOL/ANSYS 15% (30marks) As per Timetable

in CAD

Lab

Tutorial Assignments

& Surprise Quizzes 10% (20marks) As per Timetable OB

Comprehensive

Examination 35% (70marks) 09/05/2014

Partial

OB

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 4

ME F342/C382: COMPUTER AIDED DESIGN

I/C and Lecture Section: Dr. Srinivasa Prakash Regalla

Chamber Consultancy: E116, Monday 12 to 1 PM

Lecture Venue: Room No. F108

Tutorials (Every Tuesday, 8 am):

Tutorial Instructors (2 sections): F108, F109

Pattern of Tutorial Class:

problem solving (evaluated), problem solving (practice non-evaluated), extra coverage of lecture topics, or quiz

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 5

Course Project

Step 1: The whole class will be divided into batches of four students each.

Step 2: Broad topic for each batch will be displayed on the notice board.

Step 3: Student must read the necessary material from the TB1/RB1/RB2 and other sources.

Step 4: Pro/E and/or Ansys.

Step 5: Project demonstration and submission will begin from March 15 and continue for all batches.

All projects will have been submitted latest by April 15.

6

S. No. Topic

Learning Objectives No. of

Lectures Source

Fundamentals of Computer Aided Design and Geometric Modeling

Part-I. Introduction

1 CAD software and CAD hardware

Introduction, 3D modeling and viewing, modeling

aids and tools, engineering drawings, CAD

programming

3

TB: Ch-1 to 4

2 Computer simulation tools Primer on MATLAB 1 TB: Ch-5

Part-II: Geometric Modeling

3 Parametric curves Geometric Modeling: Curves, theory and MATLAB

modeling 4 TB: Ch-6

4 Parametric surfaces Geometric Modeling: Surfaces and NURBS, theory

and MATLAB modeling 4 TB: Ch-7 & 8

5 Parametric solids Geometric Modeling: Solids and Features, theory

and Pro/E modeling 3 TB: Ch-9

Part-III: Computer Graphics

6 Transformations 2-D and 3-D Geometric Transformations 3 TB: Ch-12

Part-IV: Product Design and Development & Product Data/Lifecycle Management

7

Finite Element Method: Modeling

and analysis of solid mechanics

and heat transfer problems using

FEM packages

Fundamental concepts, matrix algebra and Gaussian

elimination 3

TB: Ch-17 &

RB1: Ch-11 &

RB2

One-dimensional problems 4

Two-dimensional problems 5

Beams and frames and 3D problems 3

Scalar field problems and dynamic considerations 3

8 Rapid Prototyping Different RP/AM technologies and prototyping

practice 2 RB1: Ch-17

9 Collaborative Design Principles and tools 2 TB: Ch-19

10 Product Lifecycle Management Principles and tools 2 TB: Ch-23

Total 42

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 7

BOOKS AND REFERENCES

II. Textbook

Zeid , Ibrahim, Mastering CAD/CAM, Tata McGraw-Hill, 2007.

III. Reference

Srinivasa Prakash Regalla, Computer Aided Analysis and Design, IK International Publishers, New Delhi, 2010.

Chandrupatla, T. R., Belegundu, A. D., Introduction to Finite Elements in Engineering, 3rd Edition, Prentice Hall of India, 2005, New Delhi.

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 8

CHAPTER 1 - INTRODUCTION GOAL

Understand and master the nature of CAD/CAM systems, their basic

structure, their use in engineering tasks, and their use to create

geometric models of simple parts.

OBJECTIVES

After reading this chapter, you should understand the following

concepts:

Product life cycle

Scope of CAD/CAM

CAD/CAM Applications

Acquiring CAD/CAM Systems

Installing CAD/CAM Systems

Becoming familiar with CAD/CAM systems

GUIs and Help menus

Demo parts

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 9

Introduction CAD(Computer Aided Design)

CAM(Computer Aided Manufacturing)

CAE(Computer Aided Engineering)

Memory capacity, processing speed,

Interactive graphics

Quality, Cost, Delivery CIM

CAD CAE

CAM Others

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 10

Product cycle

Design

Need

Design

Spesifications

Feasibility Study with

Collecting Design Information

Design

Documentation

Design

Evaluation

Design

Optimization

Design

Analysis

Analysis

Model

Design

Conceptuali-

zation

Process

Planning

Production

Planning

Design and

Procurement of

New Tools

Order Material

NC, CNC, DNC

Programming

Producttion Quality

Control Packaging Shipping

Marketing

MANUFACTURING PROCESS

Analysis

Synthesis DESIGN PROCESS

CAD + CAE

CAM

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 11

THE CAD PROCESS

Design

Conceptualization

Design Modeling

and Simulation

Design Analysis Design

Optimization Design Evaluation

Design

Communication

and Documentation

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 12

Design &

Design Tools

(Analysis, Codes,

Heuristics etc.)

Computer

Graphics

Concepts

Geometric

Modeling

CAD

Tools

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 13

Definition of CAD tools based on

Implementation

DESIGN TOOLS + COMPUTER

HARDWARE

(central unit, display

terminals, input./output

devices)

SOFTWARE

(graphics, modeling, applications

programming)

= CAD TOOLS

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 14

CAD/CAM Systems

SOLIDWORKS, Pro/ENGINEER, CATIA, Unigraphics, I-Deas, CADKEY, AutoCAD

Programming and graphics

Java, Java 3D, C, C++, OpenGL, DirectX, VRML, FTP, Telnet, Web browsers, MATLAB

Symbolic equation solvers

Maple, MathCAD, Mathematica

THREE SETS OF SOFTWARE

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 15

CAD Based Product Life Cycle

Involves (contd.)

Design evaluation and making prototype:

Rapid Prototyping (RP)

Virtual Prototyping (VP)

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 16

Solid model of example part

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 17

Finite element analysis model of example part

Finite element meshes Load condition: case 1

Load condition: case 2

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Stress distribution on example part

Result for case1 Result for case2

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 19

Fill time distribution for example part

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 20

Physical prototype of example part

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 21

Part drawing of example part

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 22

Core, cavity, and side cores for

example part

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 23

Completely designed mold base

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 24

NC tool paths to machine mold

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 25

Kinematic analysis, etc.

Analysis model with proper abstraction

Interactive generation of analysis model

CAD Based Product Life Cycle

Involves

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 26

RP Stereo-lithography

Process

Cured Plastic

XY Scanning Ultraviolet Laser Beam

Photo-curable

Resin(Liquid)

Top of the Liquid

Elevator

Vat

Platform

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 27

Virtual Prototyping of Engine

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 28

Virtual Prototype of Equipment

Construction Equipment from John Deere (Division Inc.)

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 29

CAD Based Product cycle, Steps Involved (contd.)

Design documentation

Computer aided drafting system

Automatic drafting program

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 30

CAD Based Product cycle, Step Involved (contd.)

Computer Aided Drafting System:

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 31

CAD Based Product cycle, Steps Involved (contd.)

Further Steps:

Process plan

NC program

Robot, CMM (for inspection)

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 32

Design concept may be expressed in one or more of the following forms:

Computer aided drafting system

Geometric modeling system

Parametric modeling

Representation of Design Info

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 33

Definitions of

CAD, CAM and CAE

First of all we will look at CAM and finish

it! ->

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 34

CAM well it needs a separate course! We will simply define it!

Therefore, simply speaking: CAM is Computer Aided Manufacturing, and may be

defined as use of computers, directly or indirectly, in all activities of industrial manufacturing of machine tools, people and the various other sub-systems

GM codes and APT (Automatically Programmed Tools) are the most commonly used languages for programming to instruct the machine tools and measuring instruments

Machine tools in the CAM paradigm, are freshly termed as NC or CNC or DNC machine tools because now they are controlled by 1s and 0s (binary system) that is a computer program interpreted by a microprocessor instead of the skillful hands of a machinist

full-scale CNC machine Hardige Bridgeport GX600 vertical machining center (VMC) CAM Lab

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 35

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 36

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 37

Custom 10' x 10' Milling machine with 10 Spindles

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 38

Custom 48' x 5' CNC with 2 Sonic Welders

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 39

Sample runs!

CNC milling of a aluminium prismatic part

CNC milling of pockets and slots in a foam pad

CNC artistic contour turning of a wooden cylindrical part on a lathe

CNC machining of a baseball bat

End of the topic

Questions?

I/C: Dr. Regalla Srinivasa Prakash, Mechanical Engg., B. I. T. S., Pilani 40