COMPUTING STRESS INTENSITY FACTOR USING PARTITION OF UNITY ENRICHED NATURAL ELEMENT METHOD

The natural element method (NEM) is a recently developed meshless method, but in the analysis of fracture problems, the trial functions are not able to reflect the singular stress fields correctly, thusly the refined array of nodes around a crack tip adequately is required to obtain sufficient accuracy. A new method is proposed in this article, the near-tip asymptotic displacement functions are added to the NEM approximation using the framework of partition of unity, and the enriched approximation will be used in Galerkin procedure to obtain the linear discrete system of equilibrium differential equations. The mixed-mode stress intensity factors are evaluated by the interaction integral method. Numerical simulations illustrate that proposed technique can deal with problems containing cracks easily, and can increase accuracy compared with the non-enriched natural element method in the same discretization of nodes.