Chapter02structural Design Using Staad Pro 195

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E2-E3 CIVIL TECHNICAL

Structural Design using

STAAD PRO

WELCOME

• This is a presentation for the E2-E3 Civil Technical

Module for the Topic: Structural Design using STAAD

PRO

• Eligibility: Those officers of civil wing who have got the

Up-gradation from E2 to E3.

• This presentation is last updated on 21-3-2011.

• You can also visit the Digital library of BSNL to see this

topic.



AGENDA

Introduction

Features of STAAD PRO

Types of structures & Elements

Axis & Sign Convention in STAAD PRO

Steps of Design using STAAD PRO

Typical Command Sequence in STAAD PRO


INTRODUCTION

Use of Computers in Structural Design of Buildings

• Computers can perform complicated computations at a

high-speed therefore computer programs are used for

analysis & design of structural members.

• Computer results are dependent on effectiveness of

software as certain assumptions are made in the

development of programs.

• But now, with experience, these softwares have been

revised & updated & computer programs can be relied

upon to give accurate results.


INTRODUCTION

• Limitations of Hand Computation Methods

– Applicable for small problems

– Tedious for even medium sized problems

– 3-d analysis almost impossible

• Advantages of Computer Analysis

– Matrix methods of structural analysis

– Development of numerical techniques

– Finite element method

– 3-d analysis can be done.


STAAD PRO

Use of Computers in Structural Design of Buildings

• STAAD Pro is a very powerful program which can be

used fro 3-D analysis & is useful for analysis and

design of multi-storied buildings.

• Full range of analysis including static, P-delta,

response spectrum, time history, cable etc. and

• Steel design ,

• Concrete design and

• Timber design is available in STAAD PRO


STAAD PRO

STAAD PRO

It provides the user environment for –

• Model development (Graphical as well as input

editor)

• Model visualization on screen,

• Analysis & design, and

• Verification

• Pre and Post Processor

• Isometric and perspective view and 3D shapes.




• Object-oriented 2D/3D graphical model generation

with Flexible zoom, pan and multiple views.

• Built-in command file editor for text edit.

• Customizable structural templates for creating a

model.

• Unlimited Undo and Redo

• Pull down menus, floating tool bars, tool tip help &

quick data input through spreadsheets.

• FPS, Metric or SI units.




• Supports truss & beam members, plates, solids, linear

and non-linear cables & curvilinear beams.

• Advanced automatic load generation facilities for

area, floor & moving loads.

• Display of loads, supports, properties, joints,

members, etc

Rectangular and also cylindrical & reverse cylindrical

coordinate systems with mix and match capabilities. c




• Easy auto mesh & auto refinement of user-defined

polygonal element boundary by simple mouse clicks,

including openings & column/ wall lines.

• Joint, member/ element, mesh generation with flexible

user-controlled numbering scheme

• Import/ Export DSF, DWG and Excel files.

• Presentation quality printer plots of geometry and results

as part of run output.

• Efficient algorithm minimizes disk space requirements.




Model Generation

Easy “snap-to” construction grid for laying out beams

and columns on irregular grids.

Segments of repetitive geometry may be used to

generate complex structural models.

Generate, copy, repeat, mirror, pivot, etc. for quick and

easy geometry generation.

Comprehensive graphical editing.

Library of commonly used structures and display of

properties, loadings, supports, orientations etc.




Model Generation

Graphical specification & display of properties,

loadings, supports, orientations etc.

Import/Export of Auto Cad 2D/3D files to start model.

Access to text editor to modify model quickly through

command syntax.

User-controlled scale factors for deflected shapes.

Customizable node/member & renumbering scheme.

Analysis & Design


• Static Analysis

– Primary

– P-delta

– Non-linear

– Non-Linear Cable

• Basic Design

– Steel

– Concrete

• Dynamic analysis

– Rayleigh

– Eigen Solution

– Time History

– Response Spectrum

• Special Design

– Aluminum

– Timber

– Transmission Tower

Structure Types


Structural Types:

d

d

d

d

d

d

d

ud

d

u

u

u

d

u

u

GX

GY

GZ

d

X

Z

TRUSS (2D) TRUSS (3D)

PLANE (2D) SPACE (3D) FLOOR

Element Types


• Structural Elements

• Line

• Truss

• Beam

• Surface

• Plate/ Shell

• Surface

• Solid

d

d

d

d

u

u

u

u

d

u u

d

d

d

d

d

Boundary Condition


• Fully Restrained

• Partially restrained w/ Springs

• Inclined

• Multilinear

• Partially Restrained

Some Special Supports –

• Elastic footing

• Elastic Mat

• Multi-linear Spring

• Inclined Support

Using STAAD PRO

Using STAAD PRO for Analysis & Design of Building –

Steps In Design

• Manual design of slabs, staircases, chajjas, lintels etc.

• Preparing structural model of building

• Preparing data for STAAD PRO program at all levels

i.e load intensities at all floors & wall load etc.

• Perform Analysis after complete feeding of data and

obtain the analysis out-put.

• Once analysis is completed for different load

combination design is performed for load envelope.


Using STAAD PRO

Using STAAD PRO for Analysis & Design of Building

– Steps In Design

• STAAD PRO gives beam and column designs at all levels &

column reactions for design of foundations.

• Manual design of footings.

• After design by STAADPRO we note down area of steel for

column at various levels & grouping is done.

• For beams we note down main reinforcement & Shear

reinforcement at various sections & do detailing.

• Detailing of reinf done manually as per SP34 & IS 13920

• Prepare structural drawings using AutoCad or manually.


Steps for Static Analysis

• Geometric Modeling

• Material Properties

• Sectional Properties

• Supports : Boundary Conditions

• Loads & Load combinations

• Special Commands

• Analysis Specification

• Design Command


Geometric Modeling

• Nodal Co-ordinate Data

• Selection of Elements : Element Library

• Beam Elements : Beams, Columns, Truss Members

• Plate Elements : Structural Walls, Floor Slabs

• Plane Stress Elements : Shear Walls, Floor Slabs Acting

As Rigid Diaphragm To Lateral Loading

• Solid Elements : Thick Raft, Block Foundations

Surface Element:

– Rectangular

– Default Division 10X10, no. can be controlled

– Mainly introduced for Shear Wall Modeling & Design


Sectional & Material Properties

• Beam Elements : Cross Section• Plate Elements : Thickness• Solid Elements : NIL• Material means a set of:

– Modulus of Elasticity– Poisson’s Ratio– Weight Density– Thermal Coefficient – Damping Ratio– Shear Modulus

• Geometric Constant– Beta () Angle– Reference Point


Axis & Sign Convention


• Local & Global Axis System for Member

– Depends on Connectivity

– Upward Global Axis



•Different Axis Systems for Member Loads (Global-Y is Vertical)

Local Y Direction (UNI Y -2) Global Y Direction (UNI GY -2)

Projected Y Direction (UNI PY -2) Theory Projected Y Direction (UNI PY -2) Graphics



• Member End Forces - Transnational Degrees



Member End Forces – Rotational Degrees

LoadsSelf Weight

Joint Loads

– Concentrated Load & Moments

– Support Displacement Loads

Member Loads

– Uniform Force & Moment (Full / Partial) (d1, d2, d3)

– Concentrated Force & Moment (d1, d2)

– Floor Load & Area Load (new GX, GZ Floor Load)

– Linear Varying & Trapezoidal Load

– Pre-Stress / Post-Stress Load

– Hydrostatic Trapezoidal Load

– Temperature Load (x, y, z)

– Fixed End Load


Loads

Plate Element Loads

Pressure (Full / Partial)

Concentrated Force (x, y)

Trapezoidal & Hydrostatic

Trapezoidal Load

Surface Element Pressure

Generated Loads

Wind Load

Seismic Co-efficient Method

Repetitive Moving Load

Dynamic Loads

Time History

Response Spectrum

Combined Effect of

Loads

Combination (Algebraic,

SRSS, ABS)

Repeat Load


Codes & Shapes

• Design Codes

– IS 800 for Steel design

– IS 456 & 1893 for RCC design

• Shapes supported

– Shapes include I-Beams with or without cover plates,

channels, angles, double angles/ channels, pipes

and tubes (HSS Sections) for Steel design

– Also built-in steel tables

– Design of circular, rectangular, I and L shaped,

trapezoidal and Tee sections for RCC design.


Earthquake Analysis

• IS 1893 – 2002 (Part 1) Parameters:

– Seismic Zone Coefficient

– Response Reduction Factor

– Importance Factor

– Soil Site Factor

– Type of Structure

– Damping Ratio (obtain Multiplication Factor for Sa/g)

– Depth of Foundation below Ground Level

• Reduction of Ah due to Depth of Foundation

• Acceleration as Function of Time Period and Soil Type

• Evaluation of Base Shear

• Distribution of Lateral Storey Forces


Typical Command SequenceSTAAD SPACE

UNIT METER KN

JOINT COORDINATES

MEMBER INCIDENCES

MATERIAL CONSTANTS

MEMBER PROPERTY

SUPPORTS

DEFINE 1893 LOAD

ZONE…. RF….. I ….

JOINT WEIGHT

LOAD 1 SEISMIC X DIRECTION

LOAD 2 SEISMIC Z DIRECTION

LOAD 3 LOAD

SELFWEIGHT

LOAD 4 ….

LOAD COMB 11

PERFORM ANALYSIS

PRINT SUPPORT REACTION

START CONCRETE DESIGN

CODE INDIAN

FC ….. ALL

FYMAIN ….. ALL

FYSEC …. ALL

DESIGN COLUMN

DESIGN BEAM

END CONCRETE DESIGN

FINISH



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Chapter02structural Design Using Staad Pro 195