Forensic Engineering Investigation

Forensic Engineering Investigation is a compendium of the investigative methodologies used by engineers and scientific investigators to evaluate some of the more common types of failures and catastrophic events. In essence, the book provides analyses and methods for determining how an entity was damaged and when that damage may have legal consequences. The material covers 21 common types of failures, catastrophic events, and losses that forensic engineers routinely assess. The range of topics include wind and blasting damage to structures, vehicular accidents, fires, explosions, hail damage to roofs and exteriors, lighting damage, and industrial guarding accidents. Additionally, the book offers an extensive discussion of the scientific method as it applies to forensic science and provides tips on organizing and writing an investigative report. The book also supplies the applicable codes and standards that regulate the profession, discusses the role of the forensic engineer in court proceedings, and addresses the role management plays in industrial safety. Each chapter is self-contained, highly specific, and succinct. Even more important, the analysis in each chapter is tailored to the answering of questions usually posed in the particular circumstances under discussion. The author does not skimp on the mathematical and scientific underpinnings of the subject matter. In that sense, Forensic Engineering Investigation contains the "good stuff" that is typically omitted in less challenging texts. Booknews Describes methodologies used by engineers and scientific investigators to evaluate 21 common types of failures and catastrophic events, including wind damage to structures, vehicle accidents, fires, explosions, lightning damage, and industrial accidents. Discusses the scientific method as it applies to forensic science and provides tips on writing an investigative report. Outlines codes and standards of the profession, the role of the forensic engineer in court proceedings, and management's role in ensuring industrial safety. Mathematical and scientific underpinnings are given full treatment. Noon has written three previous books on forensic engineering. Annotation c. Book News, Inc., Portland, OR (booknews.com) Header 1 Forensic Engineering Investigation 2 Preface 5 About the Author 7 Table of Contents 9 Chapter 1: Introduction 17 1.1 Definition of Forensic Engineering 17 1.2 Investigation Pyramid 19 1.3 Eyewitness Information 22 1.4 Role in the Legal System 24 1.5 The Scientific Method 25 1.6 Applying the Scientific Method to Forensic Engineering 26 1.7 The Scientific Method and the Legal System 28 1.8 A Priori Biases 29 1.9 The Engineer as Expert Witness 30 1.10 Reporting the Results of a Forensic Engineering Investigation 32 Further Information and References 37 Chapter 2: Wind Damage to Residential Structures 39 2.1 Code Requirements for Wind Resistance 39 2.2 Some Basics about Wind 42 2.3 Variation of Wind Speed with Height 48 2.4 Estimating Wind Speed from Localized Damages 49 2.5 Additional Remarks 50 Further Information and References 51 Chapter 3: Lightning Damage to Well Pumps 52 3.1 Correlation is not Causation 52 3.2 Converse of Coincidence Argument 53 3.3 Underlying Reasons for Presuming Cause and Effect 54 3.4 A Little about Well Pumps 55 3.5 Lightning Access to a Well Pump 55 3.6 Well Pump Failures 58 3.7 Failure Due to Lightning 59 Further Information and References 61 Chapter 4: Evaluating Blasting Damage 62 4.1 Pre-Blast and Post-Blast Surveys 62 4.2 Effective Surveys 64 4.3 Types of Damages Caused by Blasting 65 4.4 Flyrock Damage 66 4.5 Surface Blast Craters 68 4.6 Air Concussion Damage 69 4.7 Air Shock Wave Damage 72 4.8 Ground Vibrations 73 4.9 Blast Monitoring with Seismographs 74 4.10 Blasting Study by U.S. Bureau of Mines, Bulletin 442 75 4.11 Blasting Study by U.S. Bureau of Mines, Bulletin 656 76 4.12 Safe Blasting Formula from Bulletin 656 77 4.13 OSM Modifications of the Safe Blasting Formula in Bulletin 656 78 4.14 Human Perception of Blasting Noise and Vibrations 79 4.15 Damages Typical of Blasting 81 4.16 Types of Damage Often Mistakenly Attributed to Blasting 84 4.17 Continuity 87 Further Information and References 89 Chapter 5: Building Collapse Due to Roof Leakage 90 5.1 Typical Commercial Buildings 1877–1917 90 5.2 Lime Mortar 92 5.3 Roof Leaks 95 5.4 Deferred Maintenance Business Strategy 95 5.5 Structural Damage Due to Roof Leaks 97 5.6 Structural Considerations 99 5.7 Restoration Efforts 102 Further Information and References 102 Chapter 6: Putting Machines and People Together 104 6.1 Some Background 104 6.2 Vision 107 6.3 Sound 108 6.4 Sequencing 110 6.5 The Audi 5000 Example 110 6.6 Guarding 112 6.7 Employer’s Responsibilities 114 6.8 Manufacturer’s Responsibilities 115 6.9 New Ergonomic Challenges 116 Further Information and References 116 Chapter 7: Determining the Point of Origin of a Fire 117 7.1 General 117 7.2 Burning Velocities and “V” Patterns 118 7.3 Burning Velocities and Flame Velocities 121 7.4 Flame Spread Ratings of Materials 124 7.5 A Little Heat Transfer Theory: Conduction and Convection 128 7.6 Radiation 132 7.7 Initial Reconnoiter of the Fire Scene 136 7.8 Centroid Method 138 7.9 Ignition Sources 139 7.10 The Warehouse or Box Method 141 7.11 Weighted Centroid Method 142 7.12 Fire Spread Indicators — Sequential Analysis 144 7.13 Combination of Methods 147 Further Information and References 147 Chapter 8: Electrical Shorting 149 8.1 General 149 8.2 Thermodynamics of a Simple” Resistive Circuit 152 8.3 Parallel Short Circuits 160 8.4 Series Short Circuits 163 8.5 Beading 166 8.6 Fuses, Breakers, and Overcurrent Protection 170 8.7 Example Situation Involving Overcurrent Protection 175 8.8 Ground Fault Circuit Interrupters 176 8.9 "Grandfathering” of GFCIs 177 8.10 Other Devices 177 8.11 Lightning Type Surges 179 8.12 Common Places Where Shorting Occurs 179 Further Information and References 186 Chapter 9: Explosions 188 9.1 General 188 9.2 High Pressure Gas Expansion Explosions 190 9.3 Deflagrations and Detonations 191 9.4 Some Basic Parameters 195 9.5 Overpressure Front 198 Further Information and References 201 Chapter 10: Determining the Point of Ignition of an Explosion 204 10.1 General 204 10.2 Diffusion and Fick’s Law 205 10.3 Flame Fronts and Fire Vectors 207 10.4 Pressure Vectors 208 10.5 The Epicenter 209 10.6 Energy Considerations 210 Further Information and References 212 Chapter 11: Arson and Incendiary Fires 213 11.1 General 213 11.2 Arsonist Profile 215 11.3 Basic Problems of Committing an Arson for Profit 216 11.4 The Prisoner’s Dilemma 218 11.5 Typical Characteristics of an Arson or Incendiary Fire 219 11.6 Daisy Chains and Other Arson Precursors 221 11.7 Arson Reporting Immunity Laws 223 11.8 Liquid Accelerant Pour Patterns 224 11.9 Spalling 226 11.10 Detecting Accelerants after a Fire 230 Further Information and References 234 Chapter 12: Simple Skids 235 12.1 General 235 12.2 Basic Equations 235 12.3 Simple Skids 236 12.4 Tire Friction 238 12.5 Multiple Surfaces 239 12.6 Calculation of Skid Deceleration 241 12.7 Speed Reduction by Skidding 241 12.8 Some Considerations of Data Error 241 12.9 Curved Skids 242 12.10 Brake Failures 243 12.11 Changes in Elevation 245 12.12 Load Shift 247 12.13 Antilock Brake Systems (ABS) 248 Further Information and References 249 Chapter 13: Simple Vehicular Falls 251 13.1 General 251 13.2 Basic Equations 251 13.3 Ramp Effects 253 13.4 Air Resistance 256 Further Information and References 258 Chapter 14: Vehicle Performance 259 14.1 General 259 14.2 Engine Limitations 259 14.3 Deviations from Theoretical Model 263 14.4 Example Vehicle Analysis 264 14.5 Braking 265 14.6 Stuck Accelerators 266 14.7 Brakes vs. the Engine 267 14.8 Power Brakes 269 14.9 Linkage Problems 270 14.10 Cruise Control 270 14.11 Transmission Problems 271 14.12 Miscellaneous Problems 272 14.13 NHTSA Study 272 14.14 Maximum Climb 273 14.15 Estimating Transmission Efficiency 275 14.16 Estimating Engine Thermal Efficiency 277 14.17 Peel-Out 277 14.18 Lateral Tire Friction 278 14.19 Bootlegger’s Turn 278 Further Information and References 280 Chapter 15: Momentum Methods 282 15.1 General 282 15.2 Basic Momentum Equations 283 15.3 Properties of an Elastic Collision 284 15.4 Coefficient of Restitution 286 15.5 Properties of a Plastic Collision 287 15.6 Analysis of Forces during a Fixed Barrier Impact 289 15.7 Energy Losses and "e” 290 15.8 Center of Gravity 292 15.9 Moment of Inertia 294 15.10 Torque 296 15.11 Angular Momentum Equations 298 15.12 Solution of Velocities Using the Coefficient of Restitution 299 15.13 Estimation of a Collision Coefficient of Restitution from Fixed Barrier Data 302 15.14 Discussion of Coefficient of Restitution Methods 304 Further Information and References 305 Chapter 16: Energy Methods 306 16.1 General 306 16.2 Some Theoretical Underpinnings 308 16.3 General Types of Irreversible Work 314 16.4 Rollovers 315 16.5 Flips 321 16.6 Modeling Vehicular Crush 327 16.7 Post-Buckling Behavior of Columns 329 16.8 Going from Soda Cans to the Old ‘Can You Drive?’ 331 16.9 Evaluation of Actual Crash Data 333 16.10 Low Velocity Impacts — Accounting for the Elastic Component 334 16.11 Representative Stiffness Coefficients 335 16.12 Some Additional Comments 337 Further Information and References 338 Chapter 17: Curves and Turns 340 17.1 Transverse Sliding on a Curve 340 17.2 Turnovers 344 17.3 Load Shifting 345 17.4 Side vs. Longitudinal Friction 346 17.5 Cornering and Side Slip 347 17.6 Turning Resistance 348 17.7 Turning Radius 349 17.8 Measuring Roadway Curvature 350 17.9 Motorcycle Turns 351 Further Information and References 351 Chapter 18: Visual Perception and Motorcycle Accidents 353 18.1 General 353 18.2 Background Information 354 18.3 Headlight Perception 355 18.4 Daylight Perception 357 18.5 Review of the Factors in Common 358 18.6 Difficulty Finding a Solution 359 Further Information and References 360 Chapter 19: Interpreting Lamp Filament Damages 361 19.1 General 361 19.2 Filaments 361 19.3 Oxidation of Tungsten 363 19.4 Brittleness in Tungsten 365 19.5 Ductility in Tungsten 365 19.6 Turn Signals 367 19.7 Other Applications 367 19.8 Melted Glass 367 19.9 Sources of Error 368 Further Information and References 369 Chapter 20: Automotive Fires 370 20.1 General 370 20.2 Vehicle Arson and Incendiary Fires 371 20.3 Fuel-Related Fires 373 20.4 Other Fire Loads under the Hood 377 20.5 Electrical Fires 377 20.6 Mechanical and Other Causes 379 Further Information and References 380 Chapter 21: Hail Damage 381 21.1 General 381 21.2 Hail Size 383 21.3 Hail Frequency 386 21.4 Hail Damage Fundamentals 388 21.5 Size Threshold for Hail Damage to Roofs 392 21.6 Assessing Hail Damage 395 21.7 Cosmetic Hail Damage — Burnish Marks 403 21.8 The Haig Report 406 21.9 Damage to the Sheet Metal of Automobiles and Buildings 409 21.10 Foam Roofing Systems 412 Further Information and References 413 Chapter 22: Blaming Brick Freeze-Thaw Deterioration on Hail 415 22.1 Some General Information about Bricks 415 22.2 Brick Grades 416 22.3 Basic Problem 417 22.4 Experiment 418 Further Information and References 418 Chapter 23: Management’s Role in Accidents and Catastrophic Events 420 23.1 General 420 23.2 Human Error vs. Working Conditions 424 23.3 Job Abilities vs. Job Demands 424 23.4 Management’s Role in the Causation of Accidents and Catastrophic Events 426 23.5 Example to Consider 427 Further Information and References 430 Further Information and References 431 Chapter 1 431 Chapter 2 432 Chapter 3 433 Chapter 4 433 Chapter 5 434 Chapter 6 435 Chapter 7 435 Chapter 8 437 Chapter 9 438 Chapter 10 440 Chapter 11 441 Chapter 12 441 Chapter 13 443 Chapter 14 443 Chapter 15 444 Chapter 16 445 Chapter 17 447 Chapter 18 447 Chapter 19 447 Chapter 20 448 Chapter 21 449 Chapter 22 450 Chapter 23 451 Forensic Engineering Investigation is a compendium of the investigative methodologies used by engineers and scientific investigators to evaluate some of the more common types of failures and catastrophic events. In essence, the book provides analyses and methods for determining how an entity was damaged and when that damage may have legal consequences. The material covers 21 common types of failures, catastrophic events, and losses that forensic engineers routinely assess. The range of topics include wind and blasting damage to structures, vehicular accidents, fires, explosions, hail damage to roofs and exteriors, lighting damage, and industrial guarding accidents. Additionally, the book offers an extensive discussion of the scientific method as it applies to forensic science and provides tips on organizing and writing an investigative report. The book also supplies the applicable codes and standards that regulate the profession, discusses the role of the forensic engineer in court proceedings, and addresses the role management plays in industrial safety. Each chapter is self-contained, highly specific, and succinct. Even more important, the analysis in each chapter is tailored to the answering of questions usually posed in the particular circumstances under discussion. The author does not skimp on the mathematical and scientific underpinnings of the subject matter. In that sense, Forensic Engineering Investigation contains the "good stuff" that is typically omitted in less challenging texts.