ABSTRACT
A number of crash pulse approximations and techniques have been developed for the characterization. These are divided into two major categories according to whether or not the initial deceleration is zero. • Pulse approximations with non-zero initial deceleration
* Average Square Wave (ASW) * Equivalent Square Wave (ESW) * Tipped Equivalent Square Wave (TESW)
• Pulse approximations with zero initial deceleration * Fourier Equivalent Wave (FEW) and Sensitivity Analysis * Trapezoidal Wave Approximation (TWA) * Bi-Slope Approximation (BSA) * Basic Harmonic Pulses Each one of the approximation techniques is solved analytically for a closed-form formula which
satisfies certain boundary conditions based on the crash test results. Since the mechanism of each impact involves two distinct phases, the deformation phase and the rebound phase, the boundary conditions at the end of the deformation phase are utilized to derive the parametric relationship. The dynamic crush and/or velocity change at the end of deformation phase are the basic boundary conditions frequently used in the analysis.
