Vehicle Crash Mechanics

CRASH PULSE AND KINEMATICS Introduction Vehicle Impact Modes and Crash Data Recording Digital Filtering Practice per SAE J211 and ISO 6487 Basic Kinematic Relationships Impact and Excitation: Vehicle and Sled Test Kinematics Vehicle and Occupant Kinematics in Fixed Object Impact Kinematic Variables Case Study: Single Vehicle-Tree Impact Accident Restraint Coupling Occupant Ridedown Analysis and Energy Management References CRASH PULSE CHARACTERIZATION Introduction Moment-Area Method Pulse Approximations with Non-Zero Initial Deceleration Pulse Approximations with Zero Initial Deceleration Fourier Analysis of Crash Pulse References CRASH PULSE PREDICTION--THE CONVOLUTION METHOD Introduction Transfer Function via Convolution Integral Transfer Function and a Spring-Damper Model Belted and Unbelted Occupant Performance with Air Bag Body Mount and Torso Restraint Transfer Functions Effect of Sled and Barrier Pulses on Occupant Response Other Applications Response Inverse Filtering References BASICS OF IMPACT AND EXCITATION MODELING Introduction Impact and Excitation--Rigid Barrier and Hyge Sled Tests Ridedown Existence Criteria and Efficiency Basics of Spring and Damper Dynamic Modeling Two-Mass and Effective Mass Systems Vehicle-to-Barrier Impact: Spring-Mass Model Spring-Mass Occupant Model Subjected to Excitation Vehicle-to-Vehicle Impact: Spring-Mass Model A Maxwell Model Impact on Kelvin Model--Vehicle or Component Damping Factor and Natural Frequency from Tests Excitation on the Kelvin Model--Occupant and Restraint References RESPONSE PREDICTION BY NUMERICAL METHODS Introduction Hybrid Model--A Standard Solid Model Two Mass-Spring-Damper Model Natural Frequencies in Two-Mass System Numerical Searching Techniques Loading and Unloading Simulation A Lumped-Parameter Model--CRUSH II Side-Impact and Frontal-Offset Models References IMPULSE, MOMENTUM, AND ENERGY Introduction Background Center of Gravity and Motion Theorem Impulse and Circle of Constant Acceleration Principle of Work and Energy Vehicle Inertia Properties and Critical Sliding Velocity Rollover Crashes Eccentric Loading on Vehicle Rollover References CRASH SEVERITY AND RECONSTRUCTION Introduction Occupant Motion Under Impact and Excitation Preloading on an Occupant Central Collisions Non-Central Collisions Use of DV and BEV of Vehicles in Crash Severity Assessment Vehicle Acceleration and Crash Severity Velocity and Energy Distributions in Two-Vehicle Impact Computation of Barrier Equivalent Velocity Intermediate Mass Effect Modeling the Vehicle-to-Vehicle Compatibility Test Accident Reconstruction Methodology References