Abstract Scope |
The objective of this work is to clarify the difference between the residual stress distributions of typical welded joints (such as T joint and butt joint) without any external restraint and the residual stress distributions when these joints are involved in a square tubular column-H beam welded structure. Based on ABAQUS software, a three dimensional thermal elastic plastic finite element method (FEM) was developed to simulate the residual stress distribution in a multi-pass welded joint in the current study. In order to save computing time, an effective computational approach that combines a relatively coarse mesh design and an instantaneous heat source model was proposed to calculate the welding residual stress of large-scale welded structure. Firstly, both a fine mesh model with moving heat source and a relatively coarse mesh model with instantaneous heat source were employed to simulate the welding residual stress distribution of a thick-plate multi-pass butt-welded joint made of high strength low alloy steel. The computational accuracy of the proposed effective computational approach was verified through comparing with the results obtained by the fine mesh finite element model with moving heat source and the corresponding measured data. Then, the residual stress distributions of the typical welded joints involved in the welded structure ( under the structural restraint condition), and the typical welded joints under free state were calculated using the proposed computational approach. The simulation results indicate that the structural restraint has slight influence on the longitudinal residual stress in the welded zones and their vicinity and the thickness direction residual stress, but it can significantly affect the longitudinal residual stress far away from the welded zone and the transverse residual stress. |