Analysis of residual stresses and distortions of a titanium alloy ring-stiffened cylindrical shell

Abstract

Abstract Ring-stiffened cylindrical shell is the main pressure structure of underwater carrier equipment, and the residual stress and deformation introduced by welding of ring-ribbed frame and cylinder body pose a great threat to the performance and safety of the structure. In this paper, finite element software is used to numerically simulate the residual stress and deformation caused by fillet welding. The influence of welding position, constraint tooling and post-weld heat treatment PWHT on the residual stress and deformation is analyzed systematically. The results show that the gravity has little effect on the welding residual stress and deformation, but it has a significant impact on deformation uniformity. Under the action of restraint, the welding distortion is effectively controlled, but it will lead to the increase of the overall stress level of the structure simultaneously. Heat treatment can dramatically diminish the welding residual stress at the expense of deformation, which may result in structural maladjustment.