Three-dimensional stress analysis of tubular joint using rezone technique

Abstract

This note presents three-dimensional stress analysis results of a welded tubular T-joint under axial loading, using rezone technique. The rezone technique is used to reduce computer storage requirements, as well as solution costs, that result from the large number of degrees-of-freedom associated with three-dimensional analysis of the entire joint using solid elements. The hot-spot region around the weld toe and the weld reinforcement are modelled using three-dimensional incompatible 8-node brick and 6-node prism elements. The boundary nodal displacements for the rezoned model are obtained from plate analysis of the entire joint. The boundary values, at the plate-to-solid element transition zone, are distributed between two solid element nodes maintaining boundary displacement compatibility. The stresses at the critical lines, obtained from the rezoned analysis, are compared with those of the entire three-dimensional and plate model analyses. Key words: tubular joint, rezoned model, transition zone, boundary displacement compatibility, incompatible elements.