HYBRID-UNITE-ELEMENT ANALYSIS OF SOME NONLINEAR AND 3-DIMENSIONAL PROBLEMS OF ENGINEERING ~CT~RE ME~~AN~~S

Abstract-In this paper, efficient numerical methods for the analysis of crack-closure effects on fatigue-crack-growth-rates, in plane stress ituations, and for the solution of stress-intensity factors for arbitrary shaped surface flaws in pressure vessels, are presented. For the former problem, an elastic-plastic finite element procedure valid for the case of finite deformation gradients is developed and crack growth is simulated by the translation of near-crack-tip elements with embedded plastic singularities. For the latter problem, an embedded-elastic-singularity hybrid finite element method, which leads to a direct evaluation of K-factors, is employed. 1