Development of a varying mesh scheme for finite element crack closure analysis

• A varying mesh scheme is proposed to save computation time.
• Remeshing and variable mapping are required additional works for the scheme.
• Good variable mapping is necessary for good calculated crack opening results.
• A large amount of computation time can be saved using the new scheme.

Large amount of computation time is inevitable for finite element crack closure analysis when the crack propagates a long distance. This is because numerous elements are needed along the crack path. A method using a varying mesh technique is proposed to reduce the number of elements. In the method, a new finite element model is constructed before crack tip release, thus, compared to the conventional scheme, two additional tasks are required for the new approach: remeshing and state variable mapping. The proposed technique using a simple variable mapping produces unacceptable results for the plane strain condition. Investigations show that the residual nodal forces resulted from the mapped stresses cause the difficulty. A new remeshing method is proposed to overcome the difficulty. Also, significant computation time saving by the new technique is confirmed.

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