Estimation of crack propagation direction angle under mixed-mode loading (mode i and mode ii): generalized fracture mechanics criteria and atomistic modeling (molecular dynamics method)

This study is devoted to the estimation of the crack propagation direction angle in the plate with the central crack under mixed-mode loading (Mode I and Mode II) in an iso-tropic linear elastic medium using two approaches: the generalized criteria of continuum mechanics (the generalized maximum tangential stress criterion and the generalized strain energy density criterion) and atomistic modeling of the Cu single crystal with the central crack. Molecular dynamics simulations of the central crack's growth in a plane medium using Large-scale Molecular Massively Parallel Simulator (LAMMPS) are performed. The inter-atomic potential used in this investigation is the Embedded Atom Method (EAM) poten-tial. The specimens with the initial central crack were subjected to Mixed-Mode loadings. The crack propagation direction angles under different values of the mixed parameter in a wide range of values from pure tensile loading to pure shear loading in a wide range of temperatures are obtained and analyzed. It is shown that the crack propagation direction angles obtained by the molecular dynamics method coincide with the crack propagation direction angles given by the multi-parameter fracture criteria based on the strain energy density and the multi-parameter description of the crack-tip fields.