Dependence of crack paths on the orientation of regular 2D peridynamic grids

•Investigation into dependence of the crack paths on grid orientation.•Explanation of the problem due to the presence of “weaker directions”.•Resolving the problem by adopting an appropriate strategy in the whole domain.•Implementation with an adaptive grid refinement to reduce computational cost.

An example of dynamic crack propagation in a 2D plate is used to clearly describe a problem affecting regular peridynamic grids: the crack-path dependence on the grid orientation. The problem, potentially very damaging for a computational method devised to simulate in particular crack propagation conditions, is investigated and better understood. In order to solve it the paper proposes a strategy which involves an increase of the computational cost when applied to the whole discretized domain. The use of adaptive refinement techniques allows to apply such a strategy only where crack propagation is taking place and, in this way, drastically increases the computational efficiency.