Dynamic Stress Intensity Factors of Mode I Crack Problem for Functionally Graded Layered Structures

摘要

In this paper, the crack-tip fields in bonded functionally graded finite strips are studied. Different layers may have different nonhomogeneity properties in the structure. A bi-parameter exponential function was introduced to simulate the continuous variation of material properties. The problem was reduced as a system of Cauchy singular integral equations of the first kind by Laplace and Fourier integral transforms. Various internal cracks and edge crack and crack crossing the interface configurations are investigated, respectively. The asymptotic stress field near the tip of a crack crossing the interface is examined and it is shown that, unlike the corresponding stress field in piecewise homogeneous materials, in this case the "kink" in material property at the interface does not introduce any singularity. The influences of geometrical and physical parameters and crack interactions on the dynamic stress intensity factors were illustrated and discussed.