4569846498

More documents

Recommendations

Info

3 Multibody systems simulation software 3.1 Overview There exists a range of commercial computer packages that can be used to solve problems in multibody systems analysis. In addition to the commercial packages that may be licensed there are also programs developed by academic institutions that may be available, albeit without the level of development and support that would be expected when buying the software from an established program developer. The features described in this chapter are from MSC.ADAMS but in principle will equip the reader to understand the capabilities of other multibody systems analysis programs used in vehicle dynamics. General-purpose MBS programs are able to address a large set of problems across a wide range of engineering industries and are not restricted to the applications in vehicle dynamics discussed here. The main use of MSC. ADAMS within the automotive industry is to simulate the performance of subsystems and full vehicles. Models are increasingly being used for large amplitude non-linear vibration problems such as powertrain isolation and driveline oscillations. The analyst will often wish to validate the performance of a suspension model over a range of displacements between full bump to rebound before the assembly of a full vehicle model that may be used for ride, handling and durability studies. A detailed model may include representations of the body, subframes, suspension arms, struts, anti-roll bars, steering system, engine, drivetrain and tyres. The main analysis code consists of a number of integrated programs that perform three-dimensional kinematic, static, quasi-static or dynamic analysis of mechanical systems. These programs may be thought of as the core solver. In addition there are a number of auxiliary programs, which can be supplied to link with the core solver. These programs can be used to model vehicle tyre characteristics, automatically generate vehicle suspensions and full vehicle models, or model the human body. Once a model has been defined the core solver will assemble the equations of motion and solve them automatically. It is also possible to include differential equations directly in the solution, which allows the modelling of a variety of control systems. The software can link or interface with CAD systems, finite element programs, software used for advanced visualization or additional software modules such as those used for tyre modelling. The combined use of these systems can lead to the development of what may be referred to as virtual prototypes, that is computer models that can simulate the tests and conditions that a real prototype would be subject to during the development of a new engineering product. The extent of these interfaces involving MSC.ADAMS is illustrated in Ryan (1993) and reproduced here in Figure 3.1. Note that although the software has been continually developed since this publication Figure 3.1 is still a useful illustration of the integration of MBS software in a CAE environment.
76 Mutibody Systems Approach to Vehicle Dynamics CAD/Solid Modelling IGES Translation Mass Properties Human Factors Modelling Hydraulic, Pneumatic Subsystem Modelling Control System Modelling Body Properties, Geometry, Postures Monitors Bond-graph Models Control Laws Geometry ADAMS System Model Definition ADAMS Data Language Suspension Models, Tyre Models, Drivetrains Differential Equations Mass, Stiffness, Damping Models Vehicle Modelling Actuator Modelling F.E. Flexible Body Modelling Interactive Real-Time Kinematics Kinematic Path Optimization Plant Model Equation Generation Assembly//Initial Condition Analysis Kinematic Analysis Static/Quasi-Static Analysis Dynamic Analysis Linearization/Model Analysis ADAMS System Simulation Modules ADAMS Results Files Loads Boundary Conditions High-speed Shaded Image Animation Signal Processing Configuration Display Data Tabulation Results Plotting Superimposed Display/Animation ADAMS Simulation Results Processing Modules Photo-realistic Rendering Film-recorded Animation Fig. 3.1 Integration of MSC.ADAMS with CAE software The first step in any simulation is to prepare a data set, which will define the system being modelled. This will include a description of the rigid parts, connecting joints, motion generators, forces and compliances. With most codes the data set is user friendly in that the data statements are easily understood with few restrictions on format. For advanced applications users can often prepare their own user-written subroutines in languages such as FORTRAN 90 or ANSI ‘C’ that can be linked with the main code. For each rigid body in the system it is necessary to define the mass, centre of mass location, and mass moments of inertia. Each body will possess a set of co-ordinates, which can be defined in global or local co-ordinate systems and are considered to move with the part during the simulation. These points are used to define centre of mass locations, joint locations and orientations, force locations and directions. The relative motion between different parts in the system can usually be constrained using joints, joint primitives, couplers, gears and user-defined constraints.
Page 2 and 3:
Multibody Systems Approach to Vehic
Page 4 and 5:
Multibody Systems Approach to Vehic
Page 6 and 7:
Contents Preface Acknowledgements N
Page 8 and 9:
Contents vii 4.10.1 Problem definit
Page 10 and 11:
Contents ix 8.2.1 Active suspension
Page 12 and 13:
Preface This book is intended to br
Page 14 and 15:
Preface xiii vehicle design process
Page 16 and 17:
Acknowledgements Mike Blundell In d
Page 18 and 19:
Nomenclature xvii {z I } 1 Unit vec
Page 20 and 21:
Nomenclature xix O n Frame for part
Page 22 and 23:
Nomenclature xxi p Magnitude of re
Page 24 and 25:
1 Introduction The most cost-effect
Page 26 and 27:
Introduction 3 subsequent ‘classi
Page 28 and 29:
Introduction 5 Fig. 1.4 Linearity:
Page 30 and 31:
Introduction 7 While apparently a s
Page 32 and 33:
Introduction 9 3. The body yaws (ro
Page 34 and 35:
Introduction 11 Aspiration Definiti
Page 36 and 37:
Introduction 13 Decomposition: Synt
Page 38 and 39:
Introduction 15 The best multibody
Page 40 and 41:
Introduction 17 shows good correlat
Page 42 and 43:
Introduction 19 generated in numeri
Page 44 and 45:
Introduction 21 1.9 Benchmarking ex
Page 46 and 47:
2 Kinematics and dynamics of rigid
Page 48 and 49: Kinematics and dynamics of rigid bo
Page 100 and 101: Multibody systems simulation softwa
Page 148 and 149:
Multibody systems simulation softwa
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
4 Modelling and analysis of suspens
Page 156 and 157:
Modelling and analysis of suspensio
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Tyre characteristics and modelling
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
Page 314 and 315:
Page 316 and 317:
Page 318 and 319:
Page 320 and 321:
Page 322 and 323:
Page 324 and 325:
Page 326 and 327:
Page 328 and 329:
Page 330 and 331:
Page 332 and 333:
Page 334 and 335:
Page 336 and 337:
Page 338 and 339:
Page 340 and 341:
Page 342 and 343:
Page 344 and 345:
Page 346 and 347:
Page 348 and 349:
Page 350 and 351:
Modelling and assembly of the full
Page 352 and 353:
Page 354 and 355:
Page 356 and 357:
Page 358 and 359:
Page 360 and 361:
Page 362 and 363:
Page 364 and 365:
Page 366 and 367:
Page 368 and 369:
Page 370 and 371:
Page 372 and 373:
Page 374 and 375:
Page 376 and 377:
Page 378 and 379:
Page 380 and 381:
Page 382 and 383:
Page 384 and 385:
Page 386 and 387:
Page 388 and 389:
Page 390 and 391:
Page 392 and 393:
Page 394 and 395:
Page 396 and 397:
Page 398 and 399:
Page 400 and 401:
Page 402 and 403:
Page 404 and 405:
Page 406 and 407:
Page 408 and 409:
Page 410 and 411:
Page 412 and 413:
Page 414 and 415:
Page 416 and 417:
Page 418 and 419:
7 Simulation output and interpretat
Page 420 and 421:
Simulation output and interpretatio
Page 422 and 423:
Page 424 and 425:
down and even more difficult to asc
Page 426 and 427:
Page 428 and 429:
Page 430 and 431:
Page 432 and 433:
Page 434 and 435:
Page 436 and 437:
Page 438 and 439:
Page 440 and 441:
Page 442 and 443:
Page 444 and 445:
Page 446 and 447:
Page 448 and 449:
Page 450 and 451:
Page 452 and 453:
Page 454 and 455:
Page 456 and 457:
Page 458 and 459:
Page 460 and 461:
Page 462 and 463:
Page 464 and 465:
8 Active systems 8.1 Introduction M
Page 466 and 467:
Active systems 443 mechanical actua
Page 468 and 469:
Active systems 445 Table 8.1 MSC.AD
Page 470 and 471:
Active systems 447 Body acceleratio
Page 472 and 473:
Active systems 449 impressions of t
Page 474 and 475:
Active systems 451 For this reason,
Page 476 and 477:
Appendix A: Vehicle model system sc
Page 478 and 479:
Page 480 and 481:
Page 482 and 483:
Page 484 and 485:
Page 486 and 487:
Page 488 and 489:
Page 490 and 491:
Page 492 and 493:
Page 494 and 495:
Page 496 and 497:
Appendix B: Fortran tyre model subr
Page 498 and 499:
Page 500 and 501:
Page 502 and 503:
Page 504 and 505:
Page 506 and 507:
Page 508 and 509:
Page 510 and 511:
Appendix C: Glossary of terms Agili
Page 512 and 513:
Appendix C: Glossary of terms 489 a
Page 514 and 515:
Appendix C: Glossary of terms 491 t
Page 516 and 517:
Appendix C: Glossary of terms 493 e
Page 518 and 519:
Appendix C: Glossary of terms 495 m
Page 520 and 521:
Appendix C: Glossary of terms 497 h
Page 522 and 523:
Appendix C: Glossary of terms 499 t
Page 524 and 525:
Appendix C: Glossary of terms 501 s
Page 526 and 527:
References 503 Blundell, M.V. The m
Page 528 and 529:
References 505 Hudi, J. AMIGO - A m
Page 530 and 531:
References 507 Palmer, D. Course no
Page 532 and 533:
References 509 European ADAMS News
Page 534 and 535:
Index Abuse loads, 148 3 g bump, 14
Page 536 and 537:
Index 513 Elk Test, 1 El-Nasher, 29
Page 538 and 539:
Index 515 generalised translational
Page 540 and 541:
Index 517 steer axis inclination, 1
show all

4569846498

Create successful ePaper yourself

Delete template?

Save as template?