Determination of Highly Accurate Values of Stress Intensity Factor in a Plate of Arbitrary Form by FEM.

FEM is useful for stress analysis and used widely in general. However, it is still not necessarily easy to obtain the highly accurate values of stress intensity factors by FEM. Recently, a method for calculating the highly accurate values of mode I stress intensity factors is proposed by Nisitani, based on the usefulness of the stress values at a crack tip calculated by FEM. Although the stress value at a crack tip by FEM is finite, it is very effective as a measure of the singular stress field of the crack tip. In this study, an extension of this method to general two dimensional crack problems was made. The extended method was applied to the problems of the inclined crack, the interference of two cracks in a strip and the micro-crack in a finite plate. As the results, it was confirmed that the present method has the sufficient accuracy in all these problems.