Simulation of crack nucleation in materials with regularly arranged spherical pores under multiaxial loading conditions

A numerical study of the initial stage of crack growth in a material containing spherical pores under multiaxial compression (constrained conditions) has been carried out using the finite element method. The influence of the pore spacing and the mechanical properties of the material on the fracture localization and the direction of crack growth has been analyzed. Both brittle and ductile materials were studied. It has been established that material  properties and the mutual arrangement of defects have a significant influence on the  direction  of  propagation  of  cracks arising  on  the  stress  concentrators  (structure  defects), up to mutually perpendicular directions (for uniaxial of the characteristic sizes of the region of influence of spherical pores on each other, beyond which the stress fields of the neighboring elements of the structure do not overlap. The dependences of the sizes of this area on the elastic characteristics of the matrix material are shown. The obtained results are relevant for obtaining numerical estimates of the duration of the initial stages of quasi- brittle fracture of ceramic-based heterophase materials, refractories in particular. Ill. 6. Ref. 26. Tab. 1.