Dynamic compressive response and fracture mechanisms of ZrB2-SiC ceramic based on discrete element method

To investigate the dynamic compression behaviors of fracturing and damage evolution of ZrB2-SiC ceramic, this paper proposes a discrete element method to carry out the dynamic compressive behavior of ZrB2-SiC ceramic. This study is based on three-dimensional discrete element-finite difference coupling modeling to realize the reproduction of the splitting Hopkinson pressure bar experiment process. Micro-parameters of the linear parallel bond model are obtained by calibrating dynamic compression strengths, stress-strain curves, and fracture characteristics of ZrB2-SiC ceramic. The dynamic compressive stress-strain curve can be divided into four stages according to the microcrack evolution and acoustic emission: stage I, linear elastic stage; stage II, microcrack initiation and then stable development stage; stage III, increment stage of microcracks before peak strength; stage IV, increment stage of microcracks after peak strength. The dynamic damage evolution with strain shows a Weibull distribution. The shape and scale parameters change with strain rate. In addition, under the dynamic compression, crack initiation stress, fracture pattern, and fragment size distribution of the ZrB2-SiC ceramic composite exhibited a significant strain-rate dependence.