1、Finite Element Analysis for Design Engineers Paul M. KurowskiFinite Element Analysis for Design EngineersOther SAE titles of interest: Advanced Vehicle Technology, 2nd Edition By Heinz Heisler (Order No. R-337) An Introduction to Modern Vehicle Design By Julian Happian-Smith (Order No. R-295) For mo
2、re information or to order a book, contact SAE at 400 Commonwealth Drive, Warrendale, PA 15096-0001; phone (724) 776-4970; fax (724) 776-0790; e-mail CustomerServicesae.org; website http:/store.sae.org.Finite Element Analysis for Design Engineers Paul M. Kurowski Warrendale, Pa. Copyright 2004 SAE I
3、nternational eISBN: 978-0-7680-5310-4All rights reserved. No part of this publication may be reproduced, stored in a re- trieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. For permis
4、sion and licensing requests, contact: SAE Permissions 400 Commonwealth Drive Warrendale, PA 15096-0001 USA E-mail: permissionssae.org Tel: 724-772-4028 Fax: 724-772-4891 Library of Congress Cataloging-in-Publication Data Kurowski, Paul M. Finite element analysis for design engineers / Paul M. Kurows
5、ki. p. cm. ISBN 0-7680-1140-X 1. Finite element method. 2. Engineering designData processing. I. Title. TA347.F5K83 2004 620.0042dc22 2004054717 SAE 400 Commonwealth Drive Warrendale, PA 15096-0001 USA E-mail: CustomerServicesae.org Tel: 877-606-7323 (inside USA and Canada) 724-776-4970 (outside USA
6、) Fax: 724-776-1615 Copyright 2004 SAE International ISBN 0-7680-1140-X SAE Order No. R-349 Printed in the United States of America. Disclaimer: Every effort has been made to provide an accurate text. The author and the manu- facturers shall not be held liable for any parts developed with this book
7、or be held responsible for any inaccuracies or errors that may appear in the book.Acknowledgments I would like to thank Professor Barna Szabo and his team at Engineering Software Research at the other end of the spectrum, software manuals teach how to use FEA software. There is very little FEA liter
8、ature that takes a “middle ground“ approach and specifically addresses the needs of design engineers who use FEA as an everyday design tool. This book attempts to fill that void by focusing on an understanding of FEA fundamentals, which are explained by simple and intuitive examples that can be gras
9、ped by any engineer. This book also takes a practical approach, char- acteristic to the attitudes of design engineers, and offers readers an opportu- nity to try all discussed topics by solving downloadable exercises using either their own FEA software or the commercial FEA software StressCheck, whi
10、ch is licensed for free to readers.CHAPTER 1 INTRODUCTION 1.1 What Is Finite Element Analysis? Finite element analysis, commonly referred to as FEA, is a tool of design analysis. Therefore, it is appropriate to start our discussion with a definition of what design analysis is and how it relates to F
11、EA. Design analysis is a process of investigating certain properties of parts, assemblies, or structures. Design analysis can be conducted on real objects or on models that represent certain aspects of a real object. If models are used instead of real objects, the analysis can be conducted earlier i
12、n the design process, before the final prod- uct or even the prototypes are built. Those models can be physical models (e.g., scaled-down models, mockups, photoelastic models) or mathematical models where a certain behavior of a part or structure is captured and described by a mathematical apparatus
13、. The design analysis conducted with the use of mathematical models can be further broken down, based on what methods are used to obtain the solution. Simple mathematical models can be solved analytically, but more complex models require the use of numerical methods. Finite element analysis is one o
14、f those numerical methods used to solve com- plex mathematical models. It has numerous uses in science and engineering, but in this book we will focus on its applications to structural and thermal analysis as used in the field of mechanical engineering. We will alternate between two terms that becam
15、e synonymous in engineering practice: (1) finite element analysis (FEA), and (2) finite element method (FEM). As we will point out on numerous occasions, FEA is a powerful but demand- ing tool of engineering analysis. The expertise expected of FEA users depends on the extent and complexity of the co
16、nducted analysis but always requires familiarity with the mechanics of materials, engineering design, and other topics as required in any mechanical engineering curriculum. For this reason, many introductory FEA books offer readers a quick review of those engineer- ing fundamentals. Rather than dupl
17、icating the efforts of other authors, Chap- ter 11 of this book refers to some of those books for reference.2 Finite Element Analysis for Design Engineers 1.2 What Is “FEA for Design Engineers?“ What exactly distinguishes “FEA for design engineers“ from “regular“ FEA? To set the tone for the remaind
18、er of this book, we will highlight the most essential characteristics of FEA for design engineers, as opposed to FEA per- formed by analysts. FEA is only another design tool. For design engineers, FEA is one of many design tools and is used in addition to computer-aided design (CAD), spreadsheets, c
19、atalogs, data- bases, hand calculations, textbooks, and so forth. FEA is based on CAD models. Today, design is almost always created using CAD tools; therefore, the CAD model is the starting point for FEA. FEA occurs concurrently with the design process. Because FEA is a design tool, it should be us
20、ed concurrently with the design process. It should keep up or, better yet, drive the design process. Analysis iterations must be performed rapidly, and because results are used to make design decisions, the results must be reliable even if an inad- equate amount of input data may be available for an
21、alysis conducted early in the design process. Limitations of FEA for design engineers. As we can see, FEA used in the design environment must meet very high requirements. It must be executed quickly and accurately, although it is in the hands of design engineers rather than FEA specialists. An obvio
22、us question is: Would it be better to have a dedicated specialist perform FEA, and allow design engineers to do what they do bestdesign new products? The answer depends on the size of the organization, the types of product, the company organization and culture, and many other tan- gible and intangib
23、le factors. The general consensus is that design engi- neers should handle relatively simple types of analyses in support of the design process. More complex types of analyses, which are too complex and too time-consuming to be executed concurrently with the design pro- cess, are usually better eith
24、er handled by a dedicated analyst or contracted out to specialized consultants. Objective of FEA for design engineers. The ultimate objective of using FEA as a design tool is to change the design process from iterative cycles of “design, prototype, test“ into a stream- lined process where prototypes
25、 are used only for final design verification.Introduction 3 With the use of FEA, design iterations are moved from the physical space of prototyping and testing into the virtual space of computer-based simu- lations (Figure 1.1). Finite element analysis is not, of course, the only tool of computerize
26、d simulation used in the design process. There are others, such as computational fluid dynamics and motion analysis, jointly called the tools of computer-aided engineering (CAE). Figure 1.1. Traditional product development needs proto- types to support the design process. The FEA-driven product deve
27、lopment process uses numerical models, rather than physical prototypes, to drive the development process. 1.3 Note on Hands-On Exercises and Illustrations in This Book Based on my many years of teaching experience, I suggest that simply read- ing this book (or any other FEA book, for that matter) is
28、 not enough to allow the knowledge to “sink in.“ To assure an effective transfer of knowledge, it is necessary to complete some examples. Therefore, most topics discussed in this book are accompanied by simple but informative exercises listed at the end of related chapters. Exceptions are Chapters 9
29、 through 12, which can be considered as standalone and can be read independently of the remainder of this book. The suggested exercises are not specific to any particular software and can be solved using almost any commercial FEA software. For readers convenience, the geometry for all exercises can be downloaded in Parasolid format from .
