抄録
A new computational method is proposed for the calculation of stress intensity factors of cracks in two-and three-dimensional elastic bodies. The method is based on the weight function method, which was originally investigated by Bueckner in relation to the integral equation formulation of a crack analysis, and by Rice from the view point of a variational approach, independently. Once this weight function has been determined for a given geometry, the stress intensity factors for arbitrary loadings may be calculated by a simple integration of the product of the weight function and the applied loads. It was unfortunate that the both methods cannot easily be applied to a general three-dimensional crack problem with an arbitrary geometry. In the present study, the weight function is defined as the displacement field induced by a force couple acting on the crack faces near a crack front for a general three-dimensional crack problem. The weight function can be approximated by using a finite element solution combined with an analytical expression near the condensation point, where a hyper-singularity occurs. The validity of the proposed method will be confirmed by several simple two- and three-dimensional crack problems. As illustrative examples, a cracked I-section beam and a semi-circular surface crack in ship structural details will be analysed.
