SIMULATION OF RESIDUAL THERMAL STRESSES IN HIGHLY POROUS FIBROUS SILICON NITRIDE CERAMICS

Abstract

The residual thermal stresses induced in highly porous fibrous silicon nitride ceramics with hardening precipitate inclusions have been computed within numerical experiment. The computations have been performed employing a coupled transient linear thermoelastic problem. The initial state with zero internal stresses is observed when the material is synthesized at high temperatures. Three-dimensional representative samples of fibrous structures generated with stochastic algorithms accounting for the set microstructural parameters of the materials have been used for the simulation. The effect of the volume content and dimensions of reinforcement as silicon carbide spherical inclusions on residual thermal stresses has been demonstrated. The simulations show that the residual stresses are commonly higher than the ultimate strength of the porous materials under study.