J-integral solutions for surface crack inside pipe under bending load

In order to provide J-integral solutions for assessing the structural integrity of cracked pipes of nuclear power plants, finite element analyses were performed for circumferential surface cracks of uniform depth in pipes under bending load. Elastic and fully plastic solutions were obtained for a wide range of geometrical and material conditions. Based on the solutions obtained, a procedure for estimating J-integrals of Ramberg-Osgood materials was proposed. Through analyses under various conditions, it was shown that the estimation procedure gives reasonable solutions regardless of material and geometrical conditions and the magnitude of load. The average error in the estimated J-integrals was almost zero. (author)