Dynamic Analysis of Impact Attenuation Systems Utilizing Plastic Deformations : Case in Which Influence of Geometry Change After Initial Yield Is Considered

Abstract

A structure whose load-displacement curve due to geometry change after initial yield is expressed approximately by a cubic nonlinear curve is represented by a dynamically equivalent system consisting of a nonlinear spring and a slider, and its dynamic response to the impact of a moving mass is analyzed by means of successive approximation. This analysis is carried out with a structure made of a rigid-perfectly-plastic material, but the results are applicable to the case of an elastic-perfectly-plastic material. Numerical examples are given for a U type beam subjected to an impulsive loading at the tip.