C. T. Sun - Mechanics of Aircraft Structures

1. Chapter 1
2. Chapter 7
3. Chapter 8

1. Chapter 1
2. Chapter 2
3. Chapter 3
4. Chapter 4
5. Chapter 5
6. Chapter 6
7. Chapter 7
8. Chapter 8
9. Chapter 9

THIRD EDITION

C. T. Sun and Ashfaq Adnan

This edition first published 2021
2021 John Wiley and Sons, Inc.

Edition history
John Wiley & Sons, Inc (2e, 2006; 1e 1998)

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Library of Congress CataloginginPublication Data Applied for:

ISBN: 9781119583912

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Cover Image: guvendemir/iStock/Getty Images Plus

To my wife, Iris, and my children, Edna, Clifford, and Leslie C.T. Sun

To my loving parents Afroza Nasreen and Dr. Md. Golbar Hussain, my beautiful wife, Most, and my sons, Aayan and Aayat A. Adnan

The purpose of the third edition is to correct some typographical errors in the second edition, add 3D elasticity equations, describe methods for structural idealization, and add a number of worked out and exercise problems. The , a new discussion is added to describe structural idealizations. New example problems are added. The expansions in the remaining chapters are concentrated on new examples and exercise problems.

The authors are indebted to many students and colleagues for some corrections and valuable suggestions. In particular, Ashfaq Adnan is indebted to his former colleague late Dr. Wen Chan. Ashfaq Adnan is thankful to Aayan Adnan for his assistance in making many new drawings. Ms. Rajni Chahal and Dr. WeiTsen (Eric) Lu are acknowledged for their contributions in the workedout problems and instruction materials.

The purpose of the second edition is to correct a number of typographical errors in the first edition, add more examples and problems for the student, and introduce a few new topics, including primary warping, effects of boundary constraints, SaintVenants principle, the concept of shear lag, the Timoshenko beam theory, and a brief introduction to the effect of plasticity on fracture. All these additions are direct extensions of the existing contents in the first edition. Consequently, the backgroundbuilding chapters, and amount to about a 25% increase in the number of pages.

The author is indebted to many students and colleagues for numerous corrections and valuable suggestions. He is indebted also to Dr. G. Huang for his assistance in making many new drawings.

This book is intended for junior or senior level aeronautical engineering students with a background in the first course of mechanics of solids. The contents can be covered in a semester at a normal pace.

The selection and presentation of materials in the course of writing this book were greatly influenced by the following developments. First, commercial finite element codes have been used extensively for structural analyses in recent years. As a result, many simplified ad hoc techniques that were important in the past have lost their useful roles in structural analyses. This development leads to the shift of emphasis from the problemsolving drill to better understanding of mechanics, developing the students ability in formulating the problem, and judging the correctness of numerical results. Second, fracture mechanics has become the most important tool in the study of aircraft structure damage tolerance and durability in the past thirty years. It seems highly desirable for undergraduate students to get some exposure to this important subject, which has traditionally been regarded as a subject for graduate students. Third, advanced composite materials have gained wide acceptance for use in aircraft structures. This new class of materials is substantially different from traditional metallic materials. An introduction to the characteristic properties of these new materials seems imperative even for undergraduate students.

In response to the advent of the finite element method, consistent elasticity approach is employed. Multidimensional stresses, strains, and stressstrain relations are emphasized. Displacement, rather than strain or stress, is used in deriving the governing equations for torsion and bending problems. This approach will help the student understand the relation between simplified structural theories and 3D elasticity equations.

The concept of fracture mechanics is brought in via the original Griffiths concept of strain energy release rate. Taking advantage of its global nature and its relation to the change of the total strain energies stored in the structure before and after crack extension, the strain energy release rate can be calculated for simple structures without difficulty for junior and senior level students.