Modeling stationary and moving cracks in shells by X-FEM with CB shell elements

The continuum-based (CB) shell theory is combined with the extended finite element method (X-FEM) in this paper to model crack propagation in shells under static and dynamic situations. Both jump function and asymptotic crack tip solution are adopted for describing the discontinuity and singularity of the crack in shells. Level set method (LSM) is used to represent the crack surface and define the enriched shape functions. Stress intensity factors (SIFs) are calculated by the displacement interpolation technique to prove the capability of the method and the maximum strain is applied for the fracture criterion. Also, an efficient integration scheme for the CB shell element with cracks is proposed.