On the residual stresses in multi-pass welds: coupling of welding simulation and fatigue analysis

This paper presents a fatigue assessment for multi-pass welds based on the simulation of a welding process, a post-weld heat treatment (PWHT) and a cyclic fatigue loading. The commercial software Virtual Weld Shop is used for the modelling of a welding process and PWHT. Welding induced residual stresses and the information about the material state can then be used in the fatigue analysis of the entire engine structure by the submodeling technique in ANSYS. Based on this calculation procedure a more accurate prediction of the component lifetime is possible. In order to validate the proposed approach an experimental setup with multi-pass single bevel butt weld is investigated. Temperature evolution during welding and X-ray measured residual stresses were compared with the results of simulation as well as failure behavior after cyclic loading. The fatigue analysis, including the welding induced residual stresses based on the Findley criterion with critical plane approach, was able to predict the different crack initiation for specimens with and without PWHT. © 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM11