粘弹性双材料界面裂缝的缝端位移场及动态断裂分析

The Viscoelastic Bi-Materials Interfacial Displacement Fields in Crack Tip Vicinity and Dynamic Fracture Analysis

本文研究的是经常在实际工程中遇到的粘弹性双材料界面裂缝的动断裂问题。由于粘弹性自身的复杂性,使得粘弹性双材料界面裂缝缝端应力的奇异性较弹性呈现出更为复杂的形式,从而使动断裂问题的分析变得更为困难。根据此情况,本文采用复阻尼理论反映粘弹性体的运动规律,用复势理论和平面问题复变函数解答的科洛索夫公式推导了粘弹性双材料界面裂缝缝端位移场及动态应力强度因子的求解公式,利用特解边界元进行了粘弹性双域耦合动力响应计算,按求得的公式用位移外推法计算了单边裂纹板在动荷载作用下的动态应力强度因子。分析了粘性,弹模比和缝长对动态应力强度因子的影响,得出了一些有益的结论。

The dynamic fracture of viscoelastic bi-materials interface was discussed. Because of the complicity of viscoelasticity, the stresses singularity in the crack tip vicinity of viscoelastic bi-materials interface becomes more complicated, thus makes the dynamic fracture analysis being very difficult. According to this, the complex damping theory was adopted to reflect the kinetic laws of viscoelstic objects. The formula of viscoelastic bi-materials interfacial displacement fields in the crack tip vicinity and dynamic stress intensity factors were derived by using the complex potentials theory and Muskelishivili equations of plane viscoelasticity problem. By using the particular solution boundary method, the viscoelastic dynamic responses was computed with the bi-region coupling. According to the derived formula, the viscoelastic dynamic stress intensity factors of edge-cracked bi-materials plates under dynamic loads were computed by using numerical crack flank displacement data. The influence of viscosity, Young＇s modulus ratios, crack lengths were considered. Moreover, some beneficial conclusions were obtained.