Effect of bend angle on plastic limit loads of pipe bends under different load conditions

The effect of bend angle on plastic limit loads of pipe bends under different load conditions is presented using three-dimensional non-linear finite element analyses. Based on finite element analysis, the characteristics of deformation, stress and strain were studied and effect of bend angle on the limit load was discussed. The results show that the effect of bend angle on limit load is great both at 0 degrees similar to 120 degrees range under internal pressure, torsion moment and in-plane bending moment and at 0 degrees similar to 90 degrees under out-of-plane moment. Then existing expressions of limit load and the finite element results were compared, and the solutions of limit load under single load condition were made. The proposed unified load solutions were obtained by fitting the finite element data under internal pressure, in-plane bending moment, out-of-plane bending moment and torsion moment. The results show that the proposed unified load solutions are consistent and in good agreement with the current finite element results. (C) 2017 Elsevier Ltd. All rights reserved.