Finite element analysis of damage in pipeline bends

Abstract

The present paper describes a numerical formulation for the analysis of damage in steel pipeline bends. In particular, the numerical implementation of Gurson plasticity model is described in the framework of a special element, referred to as "tube element". This is a three-node element, which simulates pipe behavior combining longitudinal deformation with cross-sectional ovalization and warping. The numerical results obtained with the tube elements are compared with results obtained with selective integrated Heterosis elements. The constitutive equations are integrated through an Euler-backward numerical scheme, enforcing the condition of zero stress in the radial direction of the pipe. Results for isotropic hardening have been obtained.