倾斜应力作用下垂直于功能梯度材料夹层的币型裂纹扩展问题

分析了功能梯度材料中币型裂纹扩展问题。该裂纹体受有与裂纹面成任意角度的张应力或压应力,裂纹垂直于无限域中功能梯度材料夹层。假定非均匀介质的功能梯度材料夹层与两个半无限域完全结合,其弹性模量沿厚度方向变化。利用已发表的裂纹应力强度因子数据和线弹性断裂力学的叠加原理,将应力强度因子耦合于最小应变能密度因子断裂判据,讨论了裂纹扩展的临界荷载;并讨论了荷载方向和材料性质对临界荷载的影响。

GROWTH OF PENNY-SHAPED CRACK PERPENDICULAR TO GRADED INTERFACE OF BIMATERIALS UNDER INCLINED TENSION AND COMPRESSION

The growth of a penny-shaped crack in a functionally graded material is analyzed. The crack is perpendicular to the functionally graded interfacial zone between two fully bonded solids, and subject to inclined tension or compression loads. The functionally graded interfacial zone is treated as a nonhomogeneous solid layer with its elastic modulus varying in the thickness direction. With the superposition principle of linear elastic fracture mechanics the available stress intensity factors of the penny-shaped crack under uniformly normal and shear stresses are incorporated into the strain energy density factor criterion for prediction of crack growth. The results of the critical external loads that will cause the crack to grow at the most possible location and along the most possible direction are presented. The effects of external load direction and material parameters on the critical loads are also examined.