Thermal Stress Crack Stability and Propagation in Severe Thermal Environments

摘要: A fracture-mechanical analysis is presented for stability criteria and propagation behavior of thermal stress cracks in brittle ceramics environments so severe that initiation cannot be avoided. It based on a mechanical model consisting rigidly constrained, uniformly cooled thin flat plate with uniform distribution microcracks; results are qualitatively similar to those obtained three-dimensional body penny-shaped cracks. High attained materials high values surface fracture energy, low expansion Young’s modulus. On catastrophic an initially short crack, the final crack subcritical has length which independent material properties but depends only initial density. suggested very shock resistance can developed by synthesizing densities microcracks.