Numerical Simulation of Built-In Oblique Circular 3D Crack Propagation under Uniaxial Compression by the Element Free Galerkin Method

The maximum tensile stress calculation formula in the normal plane at 3D crack front local coordinates is derived from the coordinate and vector transformation. The maximal circumferential tensile stress criterion is adopted to determine the crack propagation load, orientations and steps. In the impact domain of node in 3D element free Galerkin (EFG) method, the appropriate node density is selected to ensure the calculation accuracy, and built-in oblique circular 3D crack propagation under uniaxial compression is numerically simulated. According to the numerical calculation results, cracking loads and crack propagation angles and expansion steps are analyzed and the rupture process of built-in oblique 3D crack is revealed. Besides, the rupture shape of build-in oblique 3D crack is clearly shown by interpolation method. Built-in oblique circular 3D crack begins to rupture from the point of 80° to two sides but not the tip of crack. The closer the distance from the crack tip is, the longer the propagation steps are and the smaller the propagation angles are. The longer the distance from the crack tip is, the smaller the propagation steps are and the larger the propagation angles are. The crack does not rupture within [-30°, 30°]. This is a new phenomenon found in the rupture process of built-in 3D crack.