An Extended Finite Element (XFEM) Approach for Crack Analysis in Composite Media

A new approach is proposed to model a crack in orthotropic composite media using the extendedfinite element method (xfem). the xfem uses the concept ofpartition ofunity in addition to meshless basicidea of approximating a field variable by its values at a set of surrounding nodes. as a result, higher orderapproximations can be designed with almost the same total number of degrees offreedom. in this procedure,by using meshless based ideas, elements containing a crack are not required to conform to crack edges.therefore mesh generation is performed without any consideration of crack conformations for elements andthe method has the ability of extending the crack without any remeshing. furthermore, the type of elementsaround the crack-tip is the same as other parts of the finite element model and the number of nodes andconsequently degrees of freedom are reduced considerably in comparison to the classical finite elementmethod. developed orthotropic enrichment functions are further modified to enable modeling isotropicproblems.