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.