THE COMPUTATION OF 2-D STRESS INTENSITY FACTORS USING HYBRID MONGREL DISPLACEMENT FINITE-ELEMENTS

A new approach for the analysis of stress fields around a crack is proposed on the basis of the formulation of hybrid mongrel displacement finite element concept which secured monotonic convergence. The use of a special singular element concept which contains the series of singularity of stress field permits to obtain directly or indirectly the stress intensity factors of modes I and II. Singular six-node triangular hybrid isoparametric elements are used by placing the mid-side node near the crack tip at the quarter point position for the behaviour of displacement field. This method is applied to several 2-D problems whose solutions are known, and it is shown that their numerical results are very accurate and convergent.