A damage formulation for continuum-kinematics-inspired peridynamics to capture fracture experiments

Peridynamics (PD) is a nonlocal continuum formulation that naturally allows for discontinuities, such as cracks. It has therefore become attractive in the field of fracture modeling. Continuum-kinematics-inspired peridynamics (CPD) is a novel peridynamic reformulation that overcomes the fundamental limitation of classical bond-based PD, i.e. a fixed Poisson's ratio. The novelty of this work is (i) the introduction of damage into the formulation of CPD and (ii) the comparison of the numerical results with fracture experiments conducted as a part of this study. In CPD, nonlocal interactions between material points are captured via one-, two-and three-neighbor interactions, allowing to measure length, area and volume changes. For each type of interaction, a separate damage variable is employed, depending on the associated strain. For a two-dimensional problem, the damage parameters of the model are derived from the classical fracture energy. In order to assess the model's performance in predicting experimental outcomes, a series of fracture experiments is performed. Diagonally loaded square plates with center cracks of varying inclination angle are tested to study different fracture modes. The results demonstrate the model's capability to capture the maximum loads and the crack paths observed in the experiments. This is the first contribution that integrates theory, computation and experiment within the framework of CPD.