脆性薄膜穿透裂纹应力强度因子的模拟分析

The stress intensity factor of a channeling crack in a brittle film with model method

针对裂纹尖端位于膜/基界面上的脆性薄膜,通过ABAQUS模拟其裂纹尖端的应力强度因子,得到在不同的弹性不匹配情况下半无限基体上脆性薄膜穿透裂纹尖端的无量纲化的应力强度因子,并与Beuth的结果进行比较,证明了其正确性。然后又对带有周期裂纹的脆性薄膜在不同的基体与薄膜厚度比H/h和不同的裂纹间距情况下进行有限元模拟,得出裂纹尖端无量纲化的应力强度因子。结果表明,无量纲化的应力强度因子随裂纹间距的增大而增大,随基体与薄膜的厚度比减小而有增大趋势。

The stress intensity factor in the crack tip of the brittle film is simulated by ABAQUS, which primarily focuses the brittle film whose crack tip located in the interface of the film/substrate system. Dimensionless stress intensity factors of the crack tips in brittle films bonded to semi-infinite substrates with different elastic mismatches are obtained, and the accuracy of the results is verified through comparisons with Beuth＇s consequences. Then brittle films with periodic cracks is simulated in the situation of different thickness ratio of substrates and films and different crack spacing, and dimensionless stress intensity factors in the crack tips are obtained. The results show that dimensionless stress intensity factor increases with the increase of crack spacing, and has an increasing trend with the reduction of the thickness ratio of the substrate and film.