Welding distortion investigation in fillet welded joint and structure based on iterative substructure method

Abstract

In this paper, prediction and controlling angular distortion in fillet welded joint and structure were investigated. First, two methods to reduce angular distortion in fillet welded joint were investigated by experimental and numerical analysis. One was to apply a constant external force in-process and the other was rigid clamping. In numerical analysis, a new in-house finite element code has been developed based on the idea of iterative substructure method (ISM) to calculate welding distortion in rational time. During experimental analysis, the constant external force was designed and applied in-process to reduce angular distortion of fillet welded joint. The results showed that the distortion can be efficiently predicted by ISM, which were in good agreement with the experimental ones. Applying constant external force in process was a more effective method to reduce distortion than using rigid clamping. In addition, with a constant load distance from weld bead, the locations of the applied constant external force and rigid clamping along the longitudinal direction (welding direction) have little influence on the magnitude of welding angular distortion. Finally, the angular distortion of a large fillet welded structure was predicted with ISM and also controlled with applying a constant external force based on the simulation results of the fillet welded joint.

Development of in situ measurement system for welding deformation using digital cameras

“…Additionally, in Fig. 7b, which is the x direction displacement distribution during welding, it is confirmed that a distribution of negative displacement is seen at the start point of the weld [1] (the bracketed numbers are shown in the figure), and a distribution of positive displacement is seen at the end point of the weld [2]. These distributions are caused by thermal expansion in the vicinity of the weld.…”

“…Displacement during welding provides important information to understand the mechanisms of welding deformation and residual stress. In particular, if welding deformation can be measured sequentially and the displacement distribution over full field can be measured, such as the results obtained by finite element analysis or other numerical analysis, 1,2 they can be valuable information.…”

In-process control of distortion in wire and arc additive manufacturing based on a flexible multi-point support fixture

“…This measure is also of great importance for the welding process [16]. For example, Kim proved that external force imposed normal to the plate during the cooling stage was effective to reduce the angular distortion during welding [17] and a similar conclusion was reached by Wang et al [18].…”

Temperature distribution effect on relation between welding heat input and angular distortion

“…8 Meanwhile, advanced modelling and simulation techniques have been variously developed: material modelling that considers microstructural effects, 9, 10 double-ellipsoidal moving-heat-source modelling, 11, 12 and the fast computation using the iterative substructure method. 13, 14 Arc-physics-based heat-source modelling has recently enabled the predictive simulation of weld angular distortion based on welding conditions. 15 Thus, computational welding mechanics has great potential for accurately predicting and clarifying the weld shrinkage and distortion.…”