Enriched meshfree collocation method with diffuse derivatives for elastic fracture

A meshfree collocation method with intrinsic enrichment for solving elastic crack problems is presented. A diffuse derivative approximation is applied in conjunction with an intrinsic enrichment of the near-tip asymptotic fields and a polynomial basis. These consistent diffuse derivatives of the approximation do not require computing the derivative of the weight function or that of the moment matrix. The local behavior of the near-tip stresses is successfully captured so that the stress intensity factors can be accurately computed. Numerical experiments demonstrate the accuracy and robustness of the method for solving elastic fracture problems.