The extended finite element method with new crack-tip enrichment functions for an interface crack between two dissimilar piezoelectric materials

Abstract

SUMMARYThis paper studies the static fracture problems of an interface crack in linear piezoelectric bimaterial by means of the extended finite element method (X-FEM) with new crack-tip enrichment functions. In the X-FEM, crack modeling is facilitated by adding a discontinuous function and crack-tip asymptotic functions to the classical finite element approximation within the framework of the partition of unity. In this work, the coupled effects of an elastic field and an electric field in piezoelectricity are considered. Corresponding to the two classes of singularities of the aforementioned interface crack problem, namely, " class and Ä class, two classes of crack-tip enrichment functions are newly derived, and the former that exhibits oscillating feature at the crack tip is numerically investigated. Computation of the fracture parameter, i.e., the J -integral, using the domain form of the contour integral, is presented. Excellent accuracy of the proposed formulation is demonstrated on benchmark interface crack problems through comparisons with analytical solutions and numerical results obtained by the classical FEM. Moreover, it is shown that the geometrical enrichment combining the mesh with local refinement is substantially better in terms of accuracy and efficiency. Copyright

Material‐dependent crack‐tip enrichment functions in XFEM for modeling interfacial cracks in bimaterials

“…Liu et al presented a direct method to extract mixed‐mode SIFs by using XFEM, which incorporates higher‐order terms of the asymptotic solution for both homogeneous and bimaterials. More recently, the XFEM was further extended to model interface cracks in orthotropic or piezoelectric bimaterials.…”

“…Liu et al 43 presented a direct method to extract mixed-mode SIFs by using XFEM, which incorporates higher-order terms of the asymptotic solution for both homogeneous and bimaterials. More recently, the XFEM was further extended to model interface cracks in orthotropic 44 or piezoelectric 45,46 bimaterials. The 12-fold enrichment functions by Sukumar et al 42 are specifically derived for bimaterials and thus lead to better results than the aforementioned 4-fold ones when modeling interface crack problems.…”