THE DEVELOPMENT AND VALIDATION OF A DYNAMIC FRACTURE PROPAGATION MODEL FOR GAS TRANSMISSION PIPELINES

A fracture control methodology that will prevent the possibility of lo ng-running crack propagation, based on the crack-tip opening angle (CT OA) is outlined here. Two aspects are considered: (1) the calculation of the maximum CTOA for a given geometry and loading and (2) the deter mination of the critical material property for fracture, (CTOA)(c). Th e vehicle for CTOA calculations was a fluid/structure/fracture interac tion inelastic dynamic computational model for fast long-running fract ure in pipelines. Validation of the approach used in this analysis was provided through quantitative comparisons with measured full-scale bu rst test data. A convenient two-specimen drop-weight tear test was use d to determine the (CTOA)(c) for line pipe steels. The linking of the latter with the quantification of a maximum CTOA for steady-state duct ile fracture, using the numerical model, provides the basis for an app roach that evaluates the conditions needed to ensure crack arrest. Cop yright (C) 1996 Elsevier Science Ltd.