Decohesion finite element with enriched basis functions for delamination

In order to address the stringent mesh size requirement of the cohesive element, currently 0.5 mm or less, the mixed-mode interface finite element is enriched with the analytical solution of an idealized beam on elastic foundation. Both the interface and the solid continuum elements are enriched; the partition of unity (PU) method is utilized to obtain the enhanced interpolation, implemented with two user elements (UEL) in the commercial package ABAQUS/Standard. The new formulation yields predictions in excellent agreement with theoretical and experimental results for a typical mode I delamination benchmark, with elements 5 mm in size.