Subscale enrichment of discontinuity for XFEM crack tip element

Övrigt konferensbidrag, 2013

In the present contribution, we propose a new XFEM based enrichment of the displacement field to allow for cracks that end or kink within an element. The basic concept relies on the fact that the crack tip element is treated on a subscale, where, in addition to the macroscopic continuous and discontinuous displacement fields, a discontinuous fluctuation field with Dirichlet boundary conditions is introduced to allow for proper representation of the discontinuous kinematics. In fact, this results in a non-standard interpolation of the discontinuity field, where additional internal nodes are utilised for the interpolation. Based on that the internal field vanish along the the crack tip element edges, it be implicitly solved for in terms of the macroscopic field. The current methodology is applied to ductile crack propagation in shells loaded at high strain rates to allow for not only crack segment through the entire shell elements (edge to edge).