OS1211 一様温度変化を受けるコーティング層界面き裂の応力拡大係数

Abstract

This paper deals with the analysis of the thermal stress intensity factor for interfacial crack beneath a coating-layer subjected to uniform change of temperature by using the finite element method. In the present method, the stress values at the crack tip calculated by FEM are used under the same mesh pattern and the stress intensity factors are evaluated from the ratio of stress values at the crack-tip-node between a given and a reference problems. This method is based on the fact that the singular stress field near the interface crack tip is controlled by the stress values at the crack tip calculated by FEM. In this calculation, for the center interface crack in the finite rectangular bonded plate, it is found that the dimensionless stress intensity factors for various material combinations are the same when the Dundurs' parameter is the constant. The dimensionless factors of interface crack beneath the coating layer are analyzed for any material combinations and the effect of material combinations and the crack size on the dimensionless stress intensity factors are considered.