含剪胀效应界面张力-位移关系的一种构造方法

为了研究异种材料界面的开裂过程,在Srensen等人工作的基础上,给出一种含剪胀效应张力-位移关系的构造方法。在界面受拉状态下,通过预先给定的剪胀函数及法向张力-位移关系导出切向张力-位移关系;在界面受压状态下,将切向张力分解为粘结力和摩擦力,摩擦力的大小与法向压力和粘结界面的破坏程度相关。该方法的结果解释了Srensen模型中切向张力-位移关系不连续及其不符合一致关联准则的原因。为便于进行数值计算,给出了用于三维有限元模型的界面刚度矩阵计算方法。选取了一种特定形式的剪胀函数,并将法向张力-位移关系假定为分段线性形式和指数形式,分别求得对应的切向张力-位移关系。最后给出了两个工程应用的例子,数值模拟结果与试验数据吻合较好。

A method for determining interfacial traction-separation law with dilatancy

Based on the work conducted by Sørensen etc., a method for determining interfacial traction-separation law with dilatancy was presented to investigate interfacial cracking processes of composites. The tangential traction-separation law was derived via a pre-defined shear dilation function and the normal traction-separation law while the interface was in tension. On the contrary, the tangential traction was decomposed into bond strength and friction strength while the interface was in compression. The friction strength is related to the normal pressure and the damage process on the cohesive interface. The results of the method explain why the tangential traction-separation law of Sørensen model is not continuous and violates the consistently coupled rule. In order to facilitate numerical simulation, expressions of interface stiffness matrix applying to three dimensional finite element models were also presented. Then a particular shear dilation function was adopted and the normal traction-separation law was assumed as multilinear form and exponential form, respectively. The corresponding tangential traction-separation law was derived applying the method presented in this paper to those functions. Finally, two examples of engineering application were given. These numerical simulation results are in good agreement with the experimental data.