A new strategy for 3D non-persistent crack propagation by the numerical manifold method with tetrahedral meshes

A new strategy for 3D non-persistent crack propagation by the numerical manifold method (NMM) with tetra-hedral meshes is proposed and corresponding computer programs are coded by C++ language. The Mohr-Coulomb failure criterion with a tensile cut-off (MCCT) is selected as the crack initiation and failure criterion for 3D crack propagation. The triangle crack tracking method is firstly used to obtain initial new crack surfaces, which are reconstructed by the cutting surface method (CFM) for tetrahedral meshes to produce the final new crack surfaces. Seven possible types of cutting surfaces that may be generated during the surface-block cutting process are discussed, and then corresponding optimal processing algorithms (OPAs) for new divisions are presented. Considering the convenience of the forthcoming contact analysis, all crack related surfaces (CRFs) for a boundary inconsistent manifold element (BIE) containing a crack are required to be further triangulated. Four numerical examples for 3D non-persistent crack propagation with tetrahedral meshes are illustrated to show the validity and applicability of the present 3D NMM algorithm and program. The numerical results are in good agreement with existing test or numerical results, thus it indicates that the new strategy for 3D non-persistent crack propagation with tetrahedral meshes is feasible and effective.