Effect of internal pressure on elastic-plastic behavior of pipe elbows under in-plane bending moments

The purpose of this study is to investigate the effect of pressure on the s train and stress analysis of pipe elbows subjected to in-plane bending mome nts. A finite element model Sor the bend was constructed and loaded with a pressure of 1200 psi and end moments taking geometric and material nonlinea rities into account using (ABAQUS) nonlinear finite element code. The press ure changes the effective stress distribution and location of the initial y ielding from the inside surface of the elbow crown to the outside surface f or the closing moment case and increases the moment of yielding. For the op ening moment case, yielding starts at the inside surface of the elbow crown with and without pressure. The pressure changes the location of the maximu m axial strain at instability Sor the closing and opening cases, and it als o changes the ovality of the cross section in both cases.