DETERMINATION OF DYNAMIC STRESS INTENSITY FACTOR IN FGM PLATES BY MLPG METHOD

In this paper, the meshless local Petrov-Galerkin (MLPG) method is used to analyze the
dynamic fracture of an isotropic FGM plate containing a center crack. The dynamic stress intensity
factors are studied under the influence of various non-homogeneity ratios. Both the moving least
square (MLS) and the direct method have been applied to estimate the shape function and to
impose the essential boundary conditions. The enriched weight function method is used to simulate
the displacement and stress field around the crack tip. Normalized dynamic stress intensity factors
(NDSIF) are calculated using the path independent integral, J*, which is formulated for the nonhomogeneous
material.
To validate the method, the homogenous center cracked plate problem is analyzed. The
obtained results show good agreement between the analytical solution and the MLPG results for
homogenous material. After validation, a center cracked plate made of FGM with two different
material gradations (along and normal to the crack length) and three different lengths of FGM zone
under the effect of step load are considered, and the following six distinct problems are studied
here.