Contributions to the Theory of Aircraft Structures

Cover......Page 1
Title page......Page 6
Preface......Page 10
Contents......Page 12
Biographical note......Page 16
Introduction......Page 22
The elastic stability of a thin-walled sphere......Page 23
Airworthiness requirements......Page 25
Stress analysis......Page 26
Stability problems......Page 27
Design, analysis and their mutual relationship......Page 29
Notes......Page 30
1. Introduction......Page 32
2. The history of the compression panel......Page 33
4. The alternative language......Page 40
6. Concluding remarks......Page 46
1. Introduction......Page 48
2. Description of the mission analysis criterion for the definition of design loads......Page 49
3. Examination of the mission analysis criterion......Page 53
4. Concluding remarks......Page 57
References......Page 59
General considerations......Page 60
A criterion for the acceptable probability of failure......Page 62
Load levels consistent with the acceptable failure rate......Page 65
Critical stresses as safety criterion......Page 68
Summary and conclusions......Page 70
Literature......Page 71
Introduction......Page 72
1. Development of airworthiness regulations......Page 73
2. The maximum load concept......Page 75
3. Manoeuvring loads......Page 77
4. Gust loads and the limit load concept......Page 79
5. Gust loads and operational usage......Page 83
6. Dynamic gust loads......Page 86
7. Gust and manoeuvre accidents......Page 88
References......Page 89
1. Introduction......Page 92
2. Dynamic schematization......Page 93
3. Experimental unsteady T-tail aerodynamics......Page 95
4. Theoretical unsteady T-tail aerodynamics......Page 99
5. Flutter model and flight flutter tests......Page 101
6. Control surface flutter......Page 107
7. Gust loading......Page 112
8. Landing impact loads......Page 115
9. Epilogue......Page 117
10. References......Page 118
1. Introduction......Page 120
2.1. General considerations......Page 121
2.2. Generalized incremental equilibrium equations......Page 122
2.3. Solution of plasticity equations......Page 123
3.1. The constitutive relation......Page 125
3.2. Application to plane stress problems......Page 126
4.1. Uniformly loaded strip weakened by a hole......Page 133
4.3. Final remarks......Page 135
6. References......Page 136
1. Introduction......Page 138
2.1. Determination of the Wiener-Hopf equation......Page 139
2.2. Solution of the Wiener-Hopf equation......Page 143
3. The semi-infinite stringer bonded to a semi-infinite sheet......Page 149
4. Normal force in the stringer......Page 153
References......Page 155
1. Introduction......Page 156
2. Shell-section method......Page 157
3. The singularities technique......Page 160
4. Approximate methods for reinforced circular holes in cylindrical shells based on the exact solutions for plates and spherical shells......Page 172
References......Page 177
2. Scope of the investigation......Page 180
3. Simplified model of the actual disk......Page 181
4.1. Differential equation and edge conditions......Page 183
4.2. Solution for the elastic case......Page 184
5. Solution for the case of yielding......Page 187
6.1. The stresses in the elastic case......Page 189
6.2. The bursting speed......Page 190
8. References......Page 191
11. On the theory of multilayer shells......Page 192
1. The governing system of differential equations......Page 193
2. Simplification of the derived system of equations......Page 199
3. Further simplification of the system of equations......Page 200
4. Discussion of results......Page 202
References......Page 204
1. Introduction......Page 206
2. The fundamental stress functions......Page 207
3. The integral equations......Page 210
4. The matrix J......Page 217
5. The solution of the integral equations......Page 219
Appendix......Page 221
Conclusions......Page 226
References......Page 227
Introduction......Page 228
The elastic behaviour of laminated composites......Page 229
The unbalanced angleply......Page 231
The pressure vessel with rotational symmetry......Page 232
The design condition......Page 233
The isotensoid......Page 234
The geometric parameter q......Page 236
Internal pressure and required number of filaments......Page 240
The cylindrical section with two winding angles......Page 244
The netting theory as a special case of the continuum theory......Page 245
Conclusions......Page 247
References......Page 248
Introduction......Page 250
Complex cylinder equations......Page 251
Edge and interior zone solutions......Page 254
The displacement boundary value problem......Page 255
Mixed boundary value problems......Page 257
References......Page 258
Introduction......Page 260
Buckling and postbuckling behavior: Results and discussion......Page 262
Appendix......Page 269
References......Page 280
1. General theory......Page 282
2. A particular example......Page 285
References......Page 291
Notation......Page 292
1. Introduction......Page 294
2. Formulation of the stability problem......Page 295
3. Stability in the self-adjoint case......Page 297
4. Instability in the case of self-adjoint operator......Page 298
5. The not self-adjoint case......Page 300
6. Concluding remarks......Page 303
References......Page 304
Formulation of the problem......Page 306
Necessary conditions for the optimum......Page 308
The dual problem......Page 309
Nature of the optimal solution......Page 311
Particular solutions. Edge r=R simply supported or free......Page 313
Particular solutions. Edge r=R clamped......Page 314
Reference......Page 316
Theoretical considerations......Page 318
Experiments......Page 322
Concluding remarks......Page 323
References......Page 324
List of symbols......Page 326
2. Equations of motion: Origin, interpretation, assumptions......Page 328
3. Steady state equations of motion for straight line flight......Page 330
3.2 Angular momentum equation......Page 331
3.3 Internal equilibrium equation......Page 332
4.1 Functional dependence of aerodynamic and thrust forces and moments......Page 335
4.2 Rigid airplane with aerodynamic influence coefficient theory......Page 336
4.3 Elastic airplane with aerodynamic and structural influence coefficient theory......Page 337
5. Use of elastic airplane equations for steady state flight......Page 340
6. The jig shape problem......Page 342
References......Page 344
List of symbols......Page 346
1. Introduction......Page 348
2. Classical linear theory......Page 349
3. Boundary effects......Page 356
4. Experimental results......Page 361
5. Imperfection sensitivity and inelastic effects......Page 365
6. Structural efficiency......Page 368
7. Conclusions......Page 372
References......Page 374
1. Introduction......Page 380
2. Properties of fibre reinforced composites......Page 382
3. The governing differential equation for sinusoidal bending of an anisotropic plate......Page 383
4. The stiffness matrix for sinusoidal bending......Page 387
5. Buckling of a long anisotropic plate with simpl y supported or clamped edges......Page 390
6. Local buckling of a class of thin orthotropic structures under uniform compression......Page 394
References......Page 398
1. Introduction......Page 400
2. The balance of rates of energies......Page 404
3. Some results for anti-plane shear motions......Page 412
4. Some results for in-plane motions......Page 416
References......Page 417
1. Introduction......Page 420
2. Formulation of the integral equation......Page 421
3. The cubic spline......Page 423
4. The approximation of the aerofoil contour and the doublet distribution by cubic splines......Page 424
5. The numerical method of solution of the integral equation......Page 427
6. Numerical results......Page 432
8. References......Page 433
1. Elementary modifications of inertia and stiffness matrices......Page 434
2. Special cases of alterations in mode shapes and frequencies......Page 435
3. Alterations of modes and eigenvalues in the general case......Page 438
5. Closely spaced eigenvalues......Page 439
References......Page 442
1. Introduction......Page 444
2. The lug joint......Page 445
3. Lugs in compression......Page 446
4. Fretting corrosion in lugs......Page 448
5. Clearance......Page 450
6. Pre- stress......Page 451
7. Expanded holes......Page 452
8. Slotted holes and flattened pins......Page 455
9. Prediction of the fatigue strength of a lug......Page 456
10. Fail-safe aspects of lugs......Page 458
11. Concluding remarks......Page 459
References......Page 460
Backcover......Page 464