MODIFIED VIRTUAL CRACK-CLOSURE TECHNIQUE USING SPECTRAL ELEMENT METHOD

This paper presents a general Chebyshev Spectral Element Method (CSEM) for obtaining strain-energy release rates for crack growth in two-dimensional isotropic materials. The procedure uses virtual crack-closure method. This method is developed for different orders of CSEM and suitable expressions for energy release rates are obtained. These expressions are evaluated by applying them to two Mode-I and two Mixed-mode problems. Two different classes of spectral elements (SEs) are formulated using Chebyshev interpolating functions, the inconsistent conventional SE formulation and the field consistent SE formulation. The convergence is investigated using both the formulations. A relative study on the efficiency of the CSEM with increasing order of polynomials is clearly brought out. The effect of crack-tip element size is also studied. It is observed that field consistent formulation always gives better results compared to inconsistent formulation. Comparisons with results from the literature for these problems show the efficiency of the CSEM.