STRESS INTENSITY FACTOR-ANALYSIS BY COMBINATION OF BOUNDARY ELEMENT AND FINITE-ELEMENT METHODS

In the present paper, a combination of the boundary element method is proposed for calculating the stress intensity factors of two-dimensional crack problems including mixed mode ones. In this method, finite elements are only allocated around a crack tip and boundary elements are used to discretize the rest of a structure. The virtual crack extension method is applied to the finite elements to obtain the stress intensity factors, together with the method for the separation of displacement components into mode I and mode II for mixed mode crack problems. The analyses are performed not only for single mode crack problems but also for mixed mode crack problems. It is found from the analyses that we can use large-sized finite elements around the crack tip for straight crack problems and select the crack extension value from the wide range of values. We can expect the stress intensity factors with the accuracy better than 1% by using the present method. © 1990.