功能梯度材料的平面断裂力学分析

A NEW MULTI-LAYERED MODEL FOR IN-PLANE FRACTURE ANALYSIS OF FUNCTIONALLY GRADED MATERIALS (FGMS)~1)

针对材料参数在厚度方向可能按任意连续变化的梯度材料，给出了一个新的分层模型．利用该模型求解了面内加载下梯度界面层和涂层中的界面裂纹问题．借助 Fourier 积分技术和传递矩阵方法，将该问题化为个 Cauchy 型奇异积分方程．通过数值求解，得到感兴趣的应力强度因子．对不同形式的杨氏模量和泊松比，计算了界而裂纹应力强度因子．结果表明泊松比的变化形式对应力强度因子影响不大，可当作常数处理，而杨氏模量的影响则很大．

A new multi-layered model is developed for fracture analysis of the functionally graded materialswith arbitrarily varying properties under in-plane loading.Based on the new model,the problem of an interfacecrack in a hmctionally graded interfacial layer or a functionally graded coating is solved.Employment of Fourierintegral transform technique and transfer matrix method reduces the boundary value problem to a Cauchysingular integral equation,which can be numerically solved to obtain the stress intensity factors(SIF_s).Forvarious forms of Young's modulus and Poisson's ratio of the functionally graded materials,SIFs are calculated.Results show that the present model is very efficient and that the effect of the Poisson's ratio's varying formson the SIFs is rather insignificant and can be reckoned as constant while the forms of Young's modulus caninfluence them notably.