弹性薄膜—基底结构界面裂纹的能量释放率

Energy release rate of interface crack of elastic film-substrate configuration

为研究弹性薄膜与基底交界面的薄膜裂纹问题,基于Beuth理论,将薄膜—基底结构的三维模型简化为平面应变模型,利用有限元分析程序计算薄膜裂纹断裂能量释放率Gs,并分析薄膜与基底的弹性错配及厚度比率对Gs的影响。结果表明:β=α/4时,Gs的幅值随着α(-1<α<1)的增大而增大。当α为负值时,Gs具有稳定性;反之,Gs具有不稳定性。Gs随着薄膜厚度的增加而增加,当hs/hf>2时,其变化较小。该研究为工程实践提供了理论参考。

In order to study the interface crack for film-substrate configuration,this paper introduces the simplification of three-dimensional model of film-substrate structure into plane strain model,the calculation of fracture energy release rate（Gs） of a cracked film-substrate configuration by finite element method,and the analysis of the influence of the different elastic mismatches and the thickness ratio between the film and the substrate on Gs.The results show that amplitude value of Gs tends to increase with the increase of α（-1〈α〈1） when β=α/4;Gs is stable when α〈0;Gs is unstable when α〉0;Gs tends to increase with the increase of thickness of the film,and there occurs a little increase of Gs when hs/hf〉2.The research provides a theoretical reference to the engineering practice.