Peridynamic simulation of fracture in quasi brittle solids using irregular finite element mesh

When subjected to increasing external loads, quasi brittle solids usually experience crack nucleation and propagation, leading to final failure of material. Numerical modeling and simulation of cracking process is an essentially important issue in mechanics and engineering science. This paper aims at applying the peridynamic method to simulate crack propagation using irregularly distributed material grids generated from finite element mesh. For post-treatment of physical fields such as strain and stress, a relevant visualization technique is developed. Various numerical tests are conducted for validation and application. Firstly, a square plate with a centrally located circular hole is considered for uniaxial tension tests performed with different non-uniform distributions of material grids. Peridynamic predictions are compared to finite element results and the influence of grid density, distribution and orientation on fracturing process is evaluated and the nonlocality of numerical results is demonstrated. Secondly, a pre-cracked plate with an off-centre circular hole is simulated under tension condition to assess the performance of locally refined grid. Finally, a square plate containing two parallel pre-existing cracks under biaxial tension is tested under different combinations of geometric parameters. The present work is in favour of developing a combined peridynamics/finite element numerical technique for efficient modelling and simulation of complex cracking problems.