Computer simulation of damage to metal-ceramic composites under shock loading

Abstract

In this work the results of studying of the mechanical behaviour of metal-ceramic composites with an aluminium matrix on mesoscale level are submitted. Computer simulation of mechanical reaction of representative volume of composite material, considered as ensemble of the interacting structural elements (ceramic particles and metal matrix), is used for studying processes of the nucleation and growth of damages on mesoscale level of metal-ceramic composites under the loading by shock pulses. The sizes of representative volume give the possibilities to enter effective mechanical parameters of a composite material. The mechanical behaviour of aluminium matrix is described by the model of the damaged elastic-plastic medium. The model of the damaged brittle solid is used for ceramics. The problem is solved in 2D statement with application of finite-difference method. The results of computer simulation show that the local tensile stresses can appear in unloading wave and can cause damages in ceramic particles. In the region of composite where two opposing unloading waves interacts (spall zone) the calculation predicts the existence of cracked ceramic particles, local damages in metal matrix and existence of mesoscale and macro-scale cracks.