Computer Aided Design & Drafting Lab - II

8/15/2019 Computer Aided Design & Drafting Lab - II

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S THY B M UNIVERSITY

CHENNAI 119

DEPARTMENT OF CIVIL ENGINEERING

B.E. VIII – SEMESTER

COMPUTER AIDED DESIGN

DRAFTING LAB -II

LAB MANUAL


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COMPUTER AIDED DESIGN AND DRAFTlNG LAB ll

AutoCADD

lntroductjon to AutoCADD Commands

Exercises:

1. Foundation Reinforcement Detailing

2. Pile Foundation Reinforcement Detailing

3. Pile Cap Reinforcement Detailing

4. Longitudinal Section of RCC Beam Reinforcement Detailing

5. Slab Reinforcement Detailing

6. Staircase Reinforcement Detailing

STAAD.Pro

Introduction to STAAD ‐ Pro.

STAAD ‐ Pre creation of input files by using the Text Editor and Graphical input Generator

STAAD ‐ Post Graphical Post processing,Viewing and Printing the output files

Exercises:

1. Analysis and Design of Continues beam with fixed at both ends

2. Analysis and Design of Continues beam with simply supported ends

3. Analysis and Design of Continues beam with over hangings 4. Analysis and Design of Propped cantilever beam with different materials

5. Analysis and Design of Continuous beam with member moment

6. Analysis and Design of Plane frames

a) Analysis and Design of Portal Frame type I

b) Analysis and Design of,Portal Frame type. ll

C) Analysis and Design of Portal Frame type lll

d) Analysis and Design of Portal Frametype lV

e) Analysis and Design of Portal Frame type V

7. Analysis and Design of trusses.


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INTRODUCTION TO AUTOCAD

INTRODUCTION:

AutoCAD is a drafting package for use in CAD. There are several drafting packages like Cad key,

DIAD, CADAM, Draftsman Delight etc. AutoCAD is a one of the popular CAD packages. It is a general

purpose computer aided design(CAD) and drafting software package for desktop computers and

workstations. AutoCAD’s, features are easy to use pull down menus, dialog boxes and icon menus to

guide the construction process. Using a mouse, we can draw geometrical entities of any complexity and

then Iayer, rotate, copy, mirror, fillet, chamter, move, stretch, scale, firm them.

AUTOCAD can be used to create a drawing using two modes, command mode and menu mode.

In command mode, the user has to type various commands on keyboard. ‘The software responds with

appropriate prompts to help the user to input the necessary information. In menu mode, the user of

software is through a menu which located on the right side of the screen or top of the screen. The menu

can be selected using the cursor control’ key on keyboard or mouse. The use of mouse may be found

easy. Menu selections can be performed through icons. Icons enable quick selection of menu.

BENEFITS

OF

CAD:

1. Improved engineering productivity.

2. Reduced engineering personal‘ requirement.

3. Drawing modifications are easier to make.

4. Improved accuracy of design.

5. Better communication.


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DRAW

COMMANDS:

1. LINE

Command; LINE


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Select object to trim: (select by mouse)

3. COPY:

Command: COPY

Select object: (select object to be copied by using mouse)

Base point/displacement/multiple: (pick any point in the object). Second

point of displacement: (picka point where to be copied).

4. MOVE:

Command: MOVE {J i

Select object: (select object to be copied by using mouse)

Base point/displacement: (pick any point in the object)

Second point of displacement: (pick a point where to be moved).

5. ERASE:

Command: ERASE

Select objects: Use any of the object, selection method to select the

objects, AUTOCAD deletes the selected group of entities from the screen.


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INTRODUCTION

TO

STAADPRO

lNTRODUCTlON:

The STAAD.Pro Graphical user interface (GUl) is normally used to create all input specifications

and all output reports and displays. These structural modeling and analysis input specifications are

stored in text file with extension ”.STD”. The objective of this is to familiarize the user with the basic

principles involved in the implementation of the various analysis/design facilities offered by the STAAD

engine. STAAD pro means Structural Analysis And Design Program.

INPUT GENERATION:

The GUI communicates with the STAAD analysis engine through the STD input file. That input file

is a text file consisting of a series of commands which are executed sequentially. The commands contain

either instructions or data pertaining to analysis and design. The STAAD input file can be created

through a text editor or the GUl modeIing facility.

TYPES OF STRUCTURES:

A structure can be defined as an assemblage of elements. STAAD is capable ofanalyzing and

designing structures consisting of frames. Plate/shell and solid elements. Almost any type of structure

can be analysed by STAAD. A Space structure which is a three dimensional framed structure with loads

applied in any plane is the most general. A Plane structure is bound by a global XY coordinate system

with loads in the same plane. A Truss structure consists of truss members which can have only axial

member forces and no bending in the members. A Floor structure is a two or three dimensional

structure having no horizontal (global or Z) movement of the structure (FX, FZ and MY are restrained at

every joint).


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UNlT SYSTLEMS:

The user is allowed to input data and request output in almost all commonly used engineering

unit systems including MKS, SI and FPS. ln input file, the user may change units as many times as

required.

STRUCTURE GEOMETRY:

A structure is an assembly of individual components such as beams, columns, slabs, plates etc. In

STAAD, frame elements and plate elements may be used to model the structural components. Typically

modeling of the structure geometry consists of two steps.

a) ldentification and description ofjoints or nodes

b) Modeling of members or elements through specification of connectivity between

joints.

COORDINATE SYSTEMS:

STAAD uses two types of coordinate system to define the structures geometry and loading

patterns. The Global codrdinate systemis an arbitrary coordinate system in space which is utilized to

specify the over all geometry and loading pattern of the structure. A Local coordinate system is

associated with each member and is utilizes in member end force output or local load specification.

a) Conventional Cartesian coordinate System: This coordinate system is at rectahgular

coordinate system(X,Y,Z) which follows the orthogonal right hand rule. This coordinate

system may be used to define the joint location and loading directions.

b) Cylinidrical codrdinate system: ln this coordinate system, the X and Y coordinates ofthe

conventional Cartesian system are replaced by R (radius) and ф (angle in degree). The Z

icoordinate is identical to Z coordinate of the Cartesian system and its positive direction is

determined by right hand rule.


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c) Reverse

cylindrical

coordinate

system: This is a cylindrical type coordinate system where the R ф

plane corresponds to the X‐Z plane of the Cartesian system. The right hand rule is followed to determine

the positive direction of the Y axis.


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MEMBER INCIDENCES SPECIFICATION:

This setof commands is used to specify members by defining connectivity between joints.

Repeat and Repeat all commands are available to facilitate generation of repetitive patterns. The

member/element incidences must be defined such that the model developed represent one single

structure only, not two or more separate structures. STAAD is capable of detecting multiple structures

automatically.

MEMBER PROPERTIES:

The following types of member property specification are available in

STAAD.

a) Prismatic property specification

1. the following prismatic properties are required for analysis are AX ‐ cross sectional area, IX ‐

Torsional constant, IY ‐moment of inertia about Y axis and IZ ‐moment of inertia about Z axis.

2. Standard steel shapes from "built in section library. A

3. User created steel tables.

4. Tapered sections.

5. Through assign command.

6. Curved specification.

b) This feature of the program allows the user to specify section names of standard steel shapes

manufactured in different countries.

c) The user can provide a customized steel table with designated names and proper corresponding

properties. The program can the find member properties from those tables. Member selection may also

be performed with the program selected members from the provided tables only.

d) Properties of tapered I sections and several types of tapered tubes may be provided through the

member property specification.

e) If one wishes to avoid the trouble of defining a specific section name, but instead wants to leave it

to the program to assign a section name by itself, the assign command is available. The section types

that may be assigned include Beam, Column, Channel, Angle and Double angle.

f) Member can be defined as being curved. Tapered sections are not permitted. The cross section

should be uniform throughout the length.

MEMBER RELEASE:

STAAD allows releases for‐both members and elements. One or both ends of members can be

released. Members are assumed to be rigidly framed into joints in accordance with the structural type

specified. When this full rigidity is not applicable, individual force components at either end of the

member can be set to zero with member release statements. By specifying release components,


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individuat degrees of freedom are removed from the analysis. Release components given in the

localcoordinate system for each member. The Partial moment release is also allowed.

TRUSS/TENSIONI/COMPRESSION:

lt is used only for members. For analyses which involve members that carry axial loads only, i.e.,

truss member, there are two methods for specifying this condition. When all the members in the

structure are truss member then the type of structure is declared as Truss and where as, when only

some of the members are truss member. The member truss command can be used where those

members will be identified separately.

MEMBER OFFSET:

Some members of a structure may not be concurrent with the incident joint thereby creating

offsets. This offset distance is specified in terms of global orlocal coordinate system (i..e., X,Y, & Z ‐

distances from the incident joint).

MATERIAL CONSTANTS:

The material constants are Modulus of Elasticity (E), Weight density (DEN), Poisson’s ratio

(POISS), Coefficient of thermal expansion (ALPHA), Composite Damping Ratio and Beta angle (BETA) or

Coordinates for any reference point(REF).

SUPPORTS:

STAAD allows specifications of supports that are parallel as well as inclined to global axes.

Support are specified as pinned, fixed or fixed with different releases (known as fixed but). A pinned

support has restraints against all translational movementgand none against rotational movement. ln

other words, a pinned support will have reactions for all forces but will resist no moments. A fixed

support has restraints against all directions of movement. The restraints of a fixed but support can be

released in any desired direction. Translational and rotational spring can also specify.

MASTER/SLAVE JOINTS:

The master/slave option is provided to enable the user to model rigid links in the structural

system. The facility can be used to model special structural element likea rigid floor diaphragm. Several

slave joints maybe provided which will be assigned same displacements as the master joint. The user is

also allowed the flexibility to choose the specific degrees of freedom for which thedisplacement

constraints will be imposed on the slaved joints. If all degrees of A freedom (FX, FY, FZ, MX, MY, and MZ)

are provided as constraints, the joints will be assumed to be rigidly connected.


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LOADS:

Loads in structure can be specified as joint load, member load. STAAD can also generate the self

weight of the structure and use it as uniformly distributed member loads in analysis. Any fraction of this

self weight can also be applied in any desired direction.

1. Joint

load: Joint loads, both forces and moments, may be applied to any free joint of a structure.

These loads act in the global coordinate system of the structure. Positive forces act in positive

coordinate direction. Any member of loads may be applied on single joint, in which case the loads will

be additive on

that joint.

2. Member load: Three types of member loads may be applied directly to a member of a structure.

These loads are uniformly distributed loads, concentrated loads and linear varying loads

(trapezoidal).Uniform loads act on the full or partial length of the member. Concentrated loads act at

any intermediate, specified point. Linearly varying loads over the full length or the member.Trapezoidal

linearly varying loads act over the full or partial length of a member. Trapezoidal load are converted into

a uniform load and several concentrated loads.


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3. Wind

load

generation: The STAAD wind load generator is capable of calculating wind loads on joints

of a structure from user specified wind intensities and exposure factors. Different wind intensities may

specified for height zones of structure. Opening in the structure may be modeling exposure factors. An

exposure factor is associated with each joint of the structure and is defined asfraction of the influence

area on which the wind load acts. Built in algorithms automatically calculate the exposed area based on

the areas bounded by members, then calculates the wind loads from the intensity and exposure input

and distributes the loads as lateral joint loads.

ANALYSIS FAClLlTlES:

The following perform analysis facilities are available in STAAD.

1. Stiffness analysis/Linear static analysis

2. Second order static analysis ‐ P delta analysis, non‐linear analysis, multi linear analysis and

member/spring tension/ compression only.

3. Dynamic analysis ‐ time history and response spectrum.


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1. To determine the support reaction and moments at each supports for the given

Continuous beam with over hangings ends


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2. To determine the support reaction and moments at each supports for the

given Continuous beam with fixed at both ends.


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given Continuous beam with Simply supported ends.


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given propped cantilever beams with two different materials.


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given Continuous beam with member moment.


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given portal frame type I


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11. To determine the support reaction for the given Roof Truss. And also

determine the tension and compression force of the the members

Documents

Computer Aided Design & Drafting Lab - II