涂层-基体系统热致开裂的影响参数研究

In this paper, the thermally driven edge-cracking behavior of a coating-substrate system has been investigated. The transient thermal stress field has been derived in a closed form for the corresponding un-cracked counterpart medium. By applying the equal thermal stresses but with opposite sign on the crack surface to be the only external load, the thermal stress intensity factors (TSIFs) at the crack tip were then obtained. The finite element method was utilized to implement the calculation. Based on dimensional analysis, the main dimensionless parameters affecting TSIFs were identified and the dependence of TSIFs on these parameters was illustrated such as dimensionless time, crack depth, thermal constants as well as mechanical constants. These results may provide some useful references for designing coating-substrate system under rapidly changing thermal environments.