Development of an Analytical and Numerical Model to Predict Elastic Wave Propagation Through Multi-metallic Systems

The behavior of multi-material layered systems that are subjected to high velocity impacts such as blast and impact is currently a topic of interest. This study investigates the impactinduced stress wave propagation through a multi-metallic layered medium subjected to low-velocity impact where only elastic waves are expected to be generated. In this study, four different test cases including a bi-metallic steel-titanium target and a steelaluminium target, a tri-metallic steel-titanium-aluminium target, and a monolithic steel target were considered. The non-linear finite element code LS-DYNA was used to develop a two-dimensional axisymmetric numerical model and its output was compared with previously published experimental results obtained from a single-stage gas gun test that are in good agreement. An analytical model was developed using MATLAB that tracks and solves the interaction of each propagation wave in the flyer-target system. The associated Reimann problem for each interaction is identified and solved. The analytical model was validated by comparing its stress-time histories with the outputs obtained by the already validated numerical model and here too, the outcomes agreed well with one another. The main findings of this study highlight the reliability of the developed numerical and analytical model in predicting elastic wave propagation through a multi-metallic system.