Geometrically nonlinear extended isogeometric analysis for cohesive fracture with applications to delamination in composites

We propose a geometrically nonlinear extended isogeometric analysis approach for cohesive fracture. A shifting technique is used to enforce compatibility in the direction perpendicular crack path, while blending has been adopted remove effect of discontinuity extension crack. Bézier extraction employed cast formulation finite element datastructure. The use sign function instead Heaviside step removes need make an assumption normal at its centreline. Examples are given illustrate methodology, including buckling delaminated structure and assessment interface contribution tangent stiffness matrix.