Thin-Walled Structures with Structural Imperfections

✍ Scribed by Luis A. Godoy

• Year: 1996
• Tongue: English
• Leaves: 433
• Edition: 1st
• Category: Library

✦ Synopsis

Thin-walled structures are designed with advanced numerical analysis techniques and constructed using sophisticated fabrication processes. There are, however, a number of factors that may result in a structure that is not exactly coincident with what was considered during the design calculations. These features may be associated with changes in the properties of the structure, in the geometry, and many others. But even small changes in the structure may sometimes produce significant changes in the response.The present work is intended to introduce professionals and researchers to the effects of imperfections on the stresses in thin-walled structures. The main idea behind the presentation is that small imperfections may introduce changes in the stresses that are nearly equal to the stresses due to the loads.The book is organized into two main parts. The first part (Chapters 1 to 6) covers the techniques for analyzing imperfections. In the second part the emphasis is on applications, which at present may be found scattered throughout many scientific and professional journals. More practical aspects of imperfections may be found in Chapter 12.It is assumed that the reader is familiar with finite element techniques, and with the basics of shell structures.

✦ Table of Contents

Front Cover......Page 1
Thin-Walled Structures with Structural Imperfections: Analysis and Behavior......Page 4
Copyright Page......Page 5
Contents......Page 12
1.1. THIN-WALLED STRUCTURES AND IMPERFECTIONS......Page 24
1.2. CLASSIFICATION OF IMPERFECTIONS IN THIN-WALLED STRUCTURES......Page 28
1.3. SOME SHELL STRUCTURES IN WHICH IMPERFECTIONS MAY BE IMPORTANT......Page 32
1.4. A FEW SITUATIONS IN WHICH IMPERFECTIONS ARE CONSIDERED......Page 40
1.5. OUTLINE OF THE BOOK......Page 44
2.1. INTRODUCTION......Page 49
2.2. IMPERFECTIONS IN GEOMETRIC PARAMETERS......Page 51
2.3. IMPERFECTIONS IN INTRINSIC PARAMETERS......Page 61
2.4. IMPERFECTIONS IN BOTH GEOMETRIC AND INTRINSIC PARAMETERS......Page 67
2.5. MAXIMUM VALUES OF THE RESPONSE......Page 70
2.6. CONCLUDING REMARKS......Page 72
3.1. INTRODUCTION......Page 75
3.2. BASIC EQUATIONS......Page 77
3.3. DIRECT ANALYSIS......Page 81
3.4. EQUIVALENT LOAD ANALYSIS......Page 84
3.5. EXPLICIT FORM OF THE EQUIVALENT LOAD......Page 90
3.6. PERTURBATION ANALYSIS......Page 96
3.7. TWO DEGREE-OF-FREEDOM SYSTEM WITH INTRINSIC IMPERFECTIONS......Page 102
3.8. FINAL REMARKS......Page 112
4.1. INTRODUCTION......Page 118
4.2. MODELS OF GEOMETRIC IMPERFECTIONS......Page 120
4.3. DIRECT ANALYSIS......Page 124
4.4. INITIAL STRAIN MODEL OF GEOMETRIC IMPERFECTIONS......Page 128
4.5. EQUIVALENT LOAD ANALYSIS......Page 132
4.6. EXPLICIT EQUIVALENT LOAD......Page 134
4.7. PERTURBATION ANALYSIS......Page 139
4.8. TWO DEGREE-OF-FREEDOM SYSTEM WITH GEOMETRIC IMPERFECTION......Page 143
4.9. IMPERFECTIONS DEFINED IN TERMS OF TWO PARAMETERS......Page 153
5.1. INTRODUCTION......Page 158
5.2. DIRECT ANALYSIS......Page 159
5.3. PERTURBATION ANALYSIS......Page 162
6.1. INTRODUCTION......Page 167
6.2. DIRECT ANALYSIS......Page 168
6.3. PERTURBATION ANALYSIS OF GEOMETRIC IMPERFECTIONS......Page 169
6.4. PERTURBATION ANALYSIS OF INTRINSIC IMPERFECTIONS......Page 173
6.5. EXAMPLE OF NON-LINEAR ANALYSIS......Page 176
6.6. FINAL REMARKS......Page 182
7.1. INTRODUCTION......Page 185
7.2. FINITE STRIPS FOR PLATE BENDING......Page 186
7.3. PLATES WITH THICKNESS CHANGES......Page 187
7.4. PLATE ASSEMBLIES WITH THICKNESS CHANGES......Page 194
7.5. PLATES WITH IMPERFECTIONS IN THE MODULUS......Page 195
7.6. FINAL REMARKS......Page 206
8.1. INTRODUCTION......Page 208
8.2. EQUIVALENT LOAD IN GEOMETRIC IMPERFECTIONS......Page 209
8.3. ELLIPTICAL PARABOLOIDAL SHELL......Page 212
8.4. FINAL REMARKS......Page 220
9.1. INTRODUCTION......Page 223
9.2. TOOLS OF ANALYSIS......Page 227
9.3. AXISYMMETRIC GEOMETRICAL IMPERFECTIONS......Page 234
9.4. LOCAL GEOMETRICAL IMPERFECTIONS......Page 246
9.5. NON LINEAR BEHAVIOR OF GEOMETRICALLY IMPERFECT SPHERES......Page 258
9.6. THICKNESS VARIATIONS IN SPHERES......Page 269
10.1. INTRODUCTION......Page 279
10.2. INFLUENCE OF MERIDIONAL IMPERFECTIONS......Page 280
10.3. INFLUENCE OF LOCAL DAMAGE......Page 286
10.4. LOCAL IMPERFECTIONS IN LARGE VERTICAL CYLINDERS......Page 291
10.5. INTERACTION BETWEEN GEOMETRICAL AND MATERIAL IMPERFECTIONS......Page 297
10.6. INTERACTION BETWEEN GEOMETRICAL IMPERFECTIONS AND CRACKS......Page 301
10.7. EXPERIMENTAL STUDIES......Page 318
10.9. CONCLUSIONS......Page 321
11.1. INTRODUCTION......Page 327
11.2. STRESSES IN A PERFECT COOLING TOWER......Page 331
11.3. INFLUENCE OF MERIDIONAL IMPERFECTIONS......Page 333
11.4. INFLUENCE OF CIRCUMFERENTIAL IMPERFECTIONS......Page 339
11.5. INFLUENCE OF LOCAL IMPERFECTIONS......Page 344
11.6. INTERACTION BETWEEN GEOMETRIC IMPERFECTIONS AND CRACKS......Page 348
11.7. CREEP OF IMPERFECT COOLING TOWERS......Page 353
11.8. FINAL REMARKS......Page 357
12.1. INTRODUCTION......Page 365
12.2. SURVEYING GEOMETRICAL IMPERFECTIONS......Page 366
12.3. DETECTION OF IMPERFECTIONS IN THE MATERIAL......Page 371
12.4. SOME RECORDS OF STRUCTURAL IMPERFECTIONS......Page 375
12.5. COLLAPSE OF STRUCTURES WITH IMPERFECTIONS......Page 384
12.6. POSSIBLE EXPLANATIONS FOR COLLAPSES......Page 389
12.7. GEOMETRIC TOLERANCE LIMITS......Page 395
12.8. FINAL REMARKS......Page 397
13.1. INTRODUCTION......Page 404
13.2. PLATO ON THE IMPERFECT WORLD, AND OTHER CONTRIBUTIONS......Page 405
13.3. OTHER APPROACHES......Page 411
A.1. INTRODUCTION......Page 415
A.2. TAYLOR EXPANSIONS......Page 416
A.3. EXPLICIT AND IMPLICIT PERTURBATION TECHNIQUES......Page 417
A.4. DEGENERATE AND NON-DEGENERATE PROBLEMS......Page 419
A.5. REGULAR AND SINGULAR PERTURBATIONS......Page 420
A.6. FINAL REMARKS......Page 421
B.1. SUMMARY OF SHELL THEORY......Page 423
B.2. APPLICATIONS......Page 427
SUBJECT INDEX......Page 430