Burst pressure analysis of pipes with geometric eccentricity and small thickness-to-diameter ratio

Two analytical models were proposed to predict the burst pressure of pipes characterized by a small thickness-to-diameter ratio and geometric eccentricity. Based on a complex stress function in a bipolar coordinate system, an analytical solution was derived for the stresses of an internally pressurized eccentric pipe, and two burst pressure prediction formulae for restrained and end-capped pipe models were obtained according the von Mises stress, which took the ultimate tensile strength (UTS) of the inner wall as the pipe bursting criterion. Next these formulae were validated by comparing the results obtained with the results of existing elastic-plastic formulae and a nonlinear finite element method. Finally, the effect of eccentricity on the burst pressure was evaluated and simplified as an empirical formula. Our research shows that the burst pressure of restrained and end-capped pipes with geometric eccentricity are nearly equivalent, and the burst pressure of an eccentric pipe is relative to that of a non-eccentric pipe. The theoretical and empirical formulae presented in this paper have broad application in the oil and gas industry to predict the burst pressure of pipes. (C) 2015 Elsevier B.V. All rights reserved.