STRESS INTENSITY FACTORS OF EMBEDDED ELLIPTIC CRACKS AND AN ASSESSMENT OF THE ASME-XI DEFECT RECHARACTERISATION CRITERIA

This paper considers aspects related to the calculation of the stress intensity factors of planar embedded defects in a solid under tension. The determination of stress intensity factor solutions using a modifi ed body force method is described, this technique having certain advan tages over existing finite element, boundary element and ordinary body force methods. Furthermore, comprehensive modified body force solutio ns are presented and discussed for a range of elliptical defect geomet ries. These solutions have then been used to assess the conservation o f the recharacterisation procedure for defects of complex geometry des cribed in Section XI of the ASME Boiler and Pressure Vessel Code. Maxi mum stress intensity factor values calculated using both the modified body force method and the ASME XI rules in conjunction with standard s olutions are compared and contrasted. The results of this analysis sho w that, by and large, ASME XI is conservative and hence safe. However, geometries for which ASME XI provides non-conservative estimates have been encountered and, in certain circumstances, this may be a cause f or concern. Copyright (C) 1996 Elsevier Science Ltd.