Predictive Modeling of Dynamic Processes (eBook)

Preface 5
Contents 7
List of Contributors 16
Introduction 20
Part I Simulation of Automotive Crash Processes 26
1 Simulation of Recoverable Foams under Impact Loading 27
Current Implementation According to Fu Chang 29
Theoretical Framework 29
Validation Tests 31
Application: Leg Impact 35
Addition of a Damage Model 37
Theoretical Framework 37
Examples 40
References 42
Introduction 28
2 The Numerical Simulation of Foam -- An Example of Inter-Industrial Synergy 44
Introduction 44
Foams -- Physical Nature and Numerical Modeling 45
Numerical Modeling of Foams in Automotive Crash 47
Impacted Foam -- The Columbia Accident 52
Summary and Conclusion 58
References 59
3 Influence of Hardening Relations on Forming Limit Curves Predicted by the Theory of Marciniak, Kuczynski, and Pokora 60
Introduction 60
Theoretical Model 62
Constitutive Equations 64
Derivation of Evolution Equations for the Onset of Instability 65
Numerical Solution Method 68
Initial Conditions 70
Validation 72
Convergence Properties 74
Influence of Different Hardening Relations on the FLCs 75
Effect of Various Quasi-Static Hardening Relations on Forming Limit Curves 76
Effect of Various Strain Rate Formulations on the Forming Limit Curves 78
Summary 80
References 81
4 The Challenge to Predict Material Failure in Crashworthiness Applications: Simulation of Producibility to Serviceability 83
Introduction 84
The Process Chain of Sheet Metal Part Manufacturing 84
Some Ideas for Failure Modelling in Forming and Crashworthiness Simulations 86
The Barlat Constitutive Model for Forming Simulations 87
Constitutive Models for Crashworthiness Applications 88
A Hybrid Approach to Estimate the Void Volume Fraction in Forming Simulations 89
A Generalized Scalar Damage Model for Forming and Crashworthiness Simulations 91
Path-Dependent Localization 93
Stress and Strain Measures 93
Linear Accumulation of the Instability Criterion 95
Nonlinear Accumulation of the Instability Criterion 96
Post Critical Behaviour 97
Damage-Dependent Yield Stress 98
Energy Dissipation and Fadeout 99
Application of a Demonstrator Part 100
Conclusions 101
References 103
5 Cohesive Zone Modeling for Adhesives 105
Introduction 106
Characterization Procedure 106
Bulk Tensile Tests 107
Coupon Tests 108
Fracture Mechanical Tests 109
Cohesive Zone Model 110
Validation 115
Application 117
Summary 120
References 120
6 Modeling the Plasticity of Various Material Classes with a Single Quadratic Yield Function 122
Introduction 122
A Quadratic Yield Function 124
Parameter Identification for Foams 127
Application to Honeycombs 129
Application to Carbon Fiber-Reinforced Plastics 132
Outlook 133
References 134
7 On the Computation of a Generalised Dynamic J-Integral and its Application to the Durability of Steel Structures 136
Introduction 136
Basic Equations 138
Theory of Configurational Forces 139
Finite Element Formulation 141
Fatigue, Stress Intensity Factor and Crack Growth Rate 142
Application to Durability Analysis 143
Summary 145
References 146
Part II Numerical Modeling of Blast and Impact Phenomena 148
8 The MAX-Analysis: New Computational and Post-Processing Procedures for Vehicle Safety Analysis 149
Introduction 149
Prediction Capabilities for Vehicle Mine and IED Blast Simulations 150
The MAX-Analysis: Unification of the Computational Results 152
Summary 154
9 Years RHT: A Review of Concrete Modelling and Hydrocode Applications 157
Introduction: Dynamic Measurements and Model Development 157
The Starting Point of the Developments 157
Equation of State for a Large-Scale Heterogeneous Composite 160
Combining Civil Engineering Knowledge and Shock Physics 162
Applications in Impact Analysis 164
Extended Validation and Sensitivity Analysis 164
Deformable Projectiles and Coupling with Explosions 168
Protecting Critical Infrastructure against Explosion Effects 169
Comparison to Engineering Models and Empirical Formula 172
From Power Plant Security to Future High-Rise-Buildings 173
Summary and Outlook 177
References 177
10 Numerical Simulations of the Penetration of Glass Using Two Pressure-Dependent Constitutive Models 180
Introduction 180
Materials 181
Experimental Techniques for Material Characterization 181
'Bomb' Technique 181
'Sleeve' Technique 183
Constitutive Model Interpretations 184
Drucker-Prager Model 184
Mohr-Coulomb Model 186
Numerical Simulation of Penetration 188
Drucker-Prager Model 189
Mohr-Coulomb Model 193
Summary and Conclusions 195
Appendix 197
References 199
11 On the main mechanisms in ballistic perforation of steel plates at sub-ordnance impact velocities 201
Introduction 202
Experimental Studies 203
Experimental Set-Up 203
Projectiles and Targets 204
Experimental Programs 205
Experimental Results 206
Effect of Projectile Impact Velocity 206
Effect of Target Thickness 207
Effect of Projectile Nose-Shape 208
Effect of Target Strength 211
Effect of Target Layering 213
Summary of Experimental Data 215
Material Modelling, Material Tests and Identification of Material Constants 216
Constitutive Relation and Fracture Criteria 218
Material Data and Model Calibration 221
Numerical Studies 223
Numerical Models 224
Some Numerical Results 225
Concluding Remarks 228
References 229
12 Dimensioning of concrete walls against small calibre impact including models for deformable penetrators and the scattering of experimental results 232
Introduction 232
Penetration and perforation of concrete walls with non-deformable penetrators 234
Deformable projectiles 237
Jacketed projectiles 237
Homogenous deformable projectiles 240
Scattering of experimental data 243
The new software-tool PenSim 245
References 247
13 Numerical Analysis of Fluiddynamic Instabilities and Pressure Fluctuations in the Near Field of a Detonation 249
Introduction 249
Physical Models 253
Numerical Methods 255
Computational Methodology 257
Results 1D, 2D and 3D Free Field 258
Results 2D Above-Ground Detonation 260
Conclusions 261
References 261
14 Numerical Simulation of Muzzle Exit and Separation Process for Sabot--Guided Projectiles at M > 1
Introduction 270
Technical Specifications / Experimental Setup 271
Numerical Solution Method 272
Simulation Results / Comparison with Experiments 273
Conclusions / Future Work 277
References 278
15 Numerical Analysis of the Supercavitating Flow about blunt Bodies 279
Introduction 279
Physical Models 281
Conservation Equations 281
Equation of State 281
Numerical Method 283
Steady State Flow Fields 284
Summary 285
References 286
16 Numerical Analysis Method for the RC Structures Subjected to Aircraft Impact and HE Detonation 288
Introduction 288
Analytical Method 289
Analysis Code 289
Material Models 290
Numerical Analyses 294
Missile Impact on RC Structure (2D) 294
HE Detonations On and Near the RC Slab (2D & 3D)
F-4 Phantom Crashing on a RC Wall (3D) 303
Boeing 747 Jet Impacting on Thick Concrete Walls (3D) 309
HE Detonation in Tunnel Structure with Inner Steel Liner (3D) 314
Conclusions 318
References 318
17 Groundshock Displacements -- Experiment and Simulation 321
Introduction 322
Experiment 322
Experimental Setup 322
Experimental results 323
MSC.DYTRAN DYMMAT14 Material Model 325
Deviatoric Behavior 325
Hydrostatic Behavior 327
Soil Data 327
Density 328
Refraction Survey and Elastic Moduli 329
Pressiometer Tests and Volumetric Crush 330
Direct Shear Tests and Yield Surface 331
Simulation 332
Simulation Setup 332
Simulation Results and Discussion 333
Conclusion 336
References 336
Part III Numerical Simulation of Hypervelocity Impact Effects 337
18 Hypervelocity Impact Induced Shock Waves and Related Equations of State 338
Introduction 338
Shock Wave Formation and the Necessity of Adequate Equations of State 339
Wave Dispersion due to Nonlinear Compressive Material Characteristics 339
Requirements to an EoS with Respect to Shock Formation 341
Equations of State for the Simulations of Shock Processes 342
Complete versus Incomplete Equations of State 342
Mie-Grüneisen Shock EoS 344
Equations of State for Porous Materials 345
References 352
19 Artificial Viscosity Methods for Modelling Shock Wave Propagation 354
Introduction 354
The Von Neumann - Richtmyer viscosity 355
Demonstration 357
Wall Heating 361
Test problems for shock viscosity formulations 361
Sod shock tube 361
Noh generic constant velocity shock 363
Saltzman piston 364
Alternative forms of artificial viscosity 366
Edge centred viscosity 367
Tensor viscosity 368
Summary 369
References 369
20 Review of Development of the Smooth Particle Hydrodynamics (SPH) Method 371
Introduction 371
Basic Formulation 376
Conservation Equations 377
Kernel Function 381
Variable Smoothing Length 382
Neighbour Search 383
SPH Shortcomings 384
Consistency 384
Tensile Instability 388
Zero-Energy Modes 393
Summary 395
References 396
21 Assessing the Resiliency of Composite Structural Systems and Materials Used in Earth-Orbiting Spacecraft to Hypervelocity Projectile Impact 401
Introduction 401
Historical Overview 404
Composite Material Panels 405
HVI Response Characterization 405
Use in MOD Protection Systems 407
Honeycomb Sandwich Panels 410
Early Work -- The 1960s and 70s 410
The 1980s and 90s 411
Recent Work 413
Conclusions 414
References 415
22 Numerical Simulation in Micrometeoroid and Orbital Debris Risk Assessment 421
Introduction 421
Ballistic Limit Simulation of a Representative Satellite Structure Wall 427
Target Definition 428
Experimental Validation of the Numerical Simulation 428
Simulation Results 430
Simulation of Hypervelocity Impact on a Representative Satellite Structure Wall Causing Penetration and Fragment Ejection 432
Target Definition 434
Experimental Validation of the Numerical Simulation 434
Simulation Results 438
Numerical Simulation of Impact Induced Disturbances in Satellite Structures 439
Target Definition 440
Experimental Validation of the Numerical Simulation 440
Simulation Results 443
Discussion and Summary 448
References 449
23 Numerical Modeling of Crater Formation by Meteorite Impact and Nuclear Explosion 451
Charles L. Mader 451
The NOBEL Code 451
Modeling the Arizona Meteor Crater 453
Modeling the SEDAN Crater Created by a Nuclear Explosion 456
Conclusions 459
References 461
Index 462