WEIGHT-FUNCTIONS FOR AN EXTERNAL LONGITUDINAL SEMIELLIPTIC SURFACE CRACK IN A THICK-WALLED CYLINDER

Mode I weight functions were derived for the deepest and surface point s of an external radial-longitudinal semi-elliptical surface crack Bz rr thick-walled cylinder with the ratio of the internal radius to wall thickness, R(i)/t = 1.0. Coefficients of a general weight function we re found using the method of two reference stress intensity factors fa r two independent stress distributions, and from properties of weight functions. Stress intensity factors calculated using the weight functi ons were compared to the finite element data for several different str ess distributions and to the boundary element method results for the L amb hoop stress in nn internally pressurized cylinder. a comparison to the ASME Pressure Vessel Code method for deriving stress intensity fa ctors Was also made. The derived weight functions enable simple calcul ations of stress intensity factors for complex stress distributions.