Numerical Simulation of Plane Wave Propagation in a Semi-infinite Media with a Linear Hardening Plastic Constitutive Model

Abstract

The theory of linear elastic waves is one of the pioneer works in the development of stress waves in soil mechanics which is involved in many practical problems in geophysics, earthquake engineering and geomechanics. However, geotechnical materials under normal engineering conditions present a plastic mechanical behavior, and the development of the theory of plastic waves was developed a century later. Till now the numerical modelling of wave propagation in a semi-infinite media with nonlinear material constitutive equation has seldom been addressed. This paper presents a systematic research on this topic. A linear hardening plastic stress-strain relationship that is a typical and representative model is chosen. A rectangular impulse load is considered to conduct the numerical and analytical studies. Numerical results are verified by the analytical solutions that is derived based on character line method. Results have shown the phenomenon of wave chase as well as the interaction of the loading slow wave and unloading fast wave. The conclusions and the proposed numerical scheme will facilitate the further investigation in many practical earthquake engineering problems.