两种粘弹塑性材料中Ⅲ型界面裂纹的断裂特性分析

Fracture Features of Interfacial Crack of Ⅲ Type in Bi material of Visco elasto plasticity

将Dugdale Barenblatt模型推广应用于两种粘弹塑性材料之间裂纹问题的分析 ,对沿切向具有跳跃边界条件的边值问题的控制方程进行富里叶变换 ,然后用逐段定积分变换方法 ,将该边值问题转化为奇异积分方程组。解方程后计算了裂纹尖端塑性区尺寸及裂纹尖端张开位移COD ,给出了应变能释放率算式。结果表明 ,裂纹尖端塑性区尺寸和COD均决定于两种材料的最小屈服极限τs。

Dugdale Barenblatt model is extended to analyse the problem of the crack on the interface between two viscoelastoplastic materials. After the governing equations are Fourier transformed, the problem of boundary conditions with tangential jumps trans formed into singular integral equations by using sectional definite integral transformation. Following solving the integral equations are the formulation of the length of the plastic zone (LPZ) ahead of the crack tip and crack tip opening displacement (COD), and the derivation of the strain energy release rate. Results reveal that the LPZ and COD are both determined by the minimum yielding stress of the two constituent materials, and the latter also rises at a gradually declining speed as time increases.