Analysis of deformation behaviour of the large diameter pipe by U-O bending process

Large diameter pipes that are made by the U-O bending process, before an expanding operation, should have sufficient material and the required profile. Therefore an analysis of condition in each forming operation is necessary in order to obtain an optimum condition under the low O-shape forming load. In this paper, a forming analysis algorithm for the pipe profile from U-formed blank to circular pipe is presented. In order to obtain the realistic behaviour in the deformation process, a theoretical analysis is made for the elastic, linear work-hardening material. In this analysis the U-shaped blank is divided into some elements and the deformation of each element is analysed by considering the history of deformation. The result obtained from forming of a blank profile has been presented and then compared to the present data reported by other researchers. Good agreements between them show the validity of the program developed.