功能梯度涂层-均匀基底周期界面裂纹动态断裂分析

研究了功能梯度涂层-均匀基底周期界面裂纹动态断裂问题。采用Fourier积分变换技术,首先将混合边值问题转化为一组三重级数方程;然后利用边界条件将混合边值问题转化为求解一个带Hilbert核的奇异积分方程;并对积分方程数值求解,获得了周期裂纹的尖端应力场。结果显示了裂纹间距、几何参数和功能梯度非均匀性对应力强度因子的影响。所获得的结果对功能梯度材料的设计及应用有参考价值。

TRANSIENT FRACTURE ANALYSIS OF PERIODIC INTERFACE CRACKS IN A FUNCTIONALLY GRADED COATING-SUBSTRATE STRUCTURE

This paper investigates the transient interface cracking between a functionally graded material (FGM) and an elastic substrate. Firstly, the mixed-boundary value problem is reduced to a typical strip to triple series equations by using Fourier integral-transform techniques. And then, application of boundary conditions reduces the solution of the mixed-boundary value problem to a singular integral equation with a Hilbert-type singular kernel. The resulting singular integral equation is solved numerically and the periodic cracks tip field is examined. Effects of crack spacing, material properties and FGM nonhomogeneity on stress intensity factors are investigated in detail. The results obtained have the reference value in the design and application of functionally graded materials.