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

Abstract

In this paper, the meshless local Petrov-Galerkin (MLPG) method is used to analyze thedynamic fracture of an isotropic FGM plate containing a center crack. The dynamic stress intensityfactors are studied under the influence of various non-homogeneity ratios. Both the moving leastsquare (MLS) and the direct method have been applied to estimate the shape function and toimpose the essential boundary conditions. The enriched weight function method is used to simulatethe 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 nonhomogeneousmaterial.To validate the method, the homogenous center cracked plate problem is analyzed. Theobtained results show good agreement between the analytical solution and the MLPG results forhomogenous material. After validation, a center cracked plate made of FGM with two differentmaterial gradations (along and normal to the crack length) and three different lengths of FGM zoneunder the effect of step load are considered, and the following six distinct problems are studiedhere.