The Use of FE Analysis In the Design Process

Prinja, N K

First Published - November 2000
Softback, 62 Pages

This document is aimed at students and practising engineers who are keen to utilise a computational technique like the finite element (FE) method in the design process. It has been assumed that the reader has some basic knowledge of the FE method.

These are two basic approaches to the design of engineering components and structures; design by rule and design by analysis. In the design by rule approach; rules and limitation set by design standard are adhered to. The design by analysis approach requires either analytical or computational effort to predict stress levels and this is where the FE method is often used. In the introductory section, the reader is made aware of the problem in using FE analysis in conjunction with design codes. If no relevant design code is available, the engineer may have to rely entirely on FE analysis and engineering judgement to substantiate the design. In section 2 the main aspects of the design of the mechanical systems are covered, followed in section 3 by a review of design by analysis which also various aspects of FE practise and assessment of a design.

The basic principles used in design codes are covered in section 4 and, through an example, it illustrated how the methodology and nomenclature of old design codes are different from those used in numerical techniques like the FE method. Since FE analysis can produce a lot of detailed stress information, it is important to appreciate the importance of various classes of stresses. The standard classification used in design codes is explained in sections 4 and 5. The numerical procedures used to post-process stress analysis results are discussed in section 6. Finally, a number of examples from various engineering disciplines are presented in section 7 to illustrate how FE analysis is used to meet the design objectives.

Contents

SUMMARY

INTRODUCTION

MECHANICAL DESIGN

DESIGN BY ANALYSIS
DESIGN PROCESS
SOME ASPECTS OF FE PRACTISE
DESIGN ASSESSMENT

PRINCIPLES USED IN THE DESIGN CODES
FE ANALYSIS TECHNIQUES Vs DESIGN CODES
CLASSIFICATIONOF STRESSES IN DESIGN CODES
DISTINCTION BETWEEN PRIMARY AND SECONDARY STRESS

UNDERSTANDING STRESS CONCENTRATION

PROCEDURE TO ASSESS NUMERICAL RESULTS

FE IN ENGINEERING DESIGN
FE IN DESIGN
FE IN SHIP BUILDING
FE IN CRANE/LIFTING APPLIANCES DESIGN

WHEN DESIGN BY FE GOES WRONG

THE FUTURE

CONCLUSIONS

REFERENCES