FAILURE ASSESSMENT OF UHTC PLATE UNDER ELEVATED TEMPERATURE

摘要

In the present study, a theoretical model is presented to assess the failure temperature for ultra-high temperature ceramics (UHTCs). Unlike traditional thermal shock theory, the parameters, such as thermal expansion coecient and Young's modulus, are considered a function of temperature in the present model. The oxide lm of UHTCs is also believed to grow under high temperature. Considering two kinds of conditions, the critical elevated temperature for delamination is calculated using Grith's theory. By establishing the relation between temperature and the mechanical properties of UHTCs, it is found that the failure behavior of UHTCs is strongly aected by the oxide lm thickness, initial temperature and the heating rate.