Dilemmas Concerning Application of Shock Response Spectrum (SRS) to Describe the Real Shock Response of a Mechanical System

摘要

The Shock Response Spectrum - SRS [BIO41, RUD96] is a very common method for evaluation of the sock severity and a popular tool for characterizing measured mechanical shocks. The aim of the research, the results of which are presented here, was the investigation of the SRS methods' limitations in the process of shock characterization. The investigation was performed by numerical simulation of the interaction between shock time-histories generated from SRS with systems represented by different lumped dynamical models and comparison to the simulation of the interaction of the measured shock with the same models. The simulation is aimed to help in determine whether the SRS is a realistic tool to characterize a mechanical shock [SHE05]. The work begins with the description of a mechanical shock time history measured under field conditions and its SRS calculation. Following this, a shock time-history is synthesized from the SRS. The original and the synthesized shock time-histories are compared in terms of: time-history, spectral content, energy content, energy localization, peak statistics, induced stress and accumulated fatigue damage. The simulation of the shock interaction with dynamical models, both for the original and synthesized shock was performed for a single and a three degree of freedom system. Finally several summarizing remarks conclude the report.