Numerical and experimental study of mitigation of welding distortion

Abstract

a b s t r a c tWelding stresses and deformations are closely related phenomena. During the heating and cooling cycles thermal strains may occur in the weld and adjacent area. The strains produced during the heating stage of welding are always accompanied by plastic deformation of the metal. The stresses resulting from these strains combine and react to produce internal forces that cause a variety of welding distortions. Welding deformation needs to be minimized and also the designer should know before hand the extent of deformation so that it can be accounted for in the design as well as in the construction stages.In this paper, heat sinking as a method of distortion mitigation has been studied. Heat sinking has been affected by circulating water through channel clamped at the bottom surface of the plates undergoing welding. The pseudolinear equivalent constant rigidity concept has been used in this investigation for thermo-mechanical analysis of plates undergoing welding with simultaneous heat sinking. The initial nonlinear problem with varying modulus dependent on temperature is transformed into a pseudolinear equivalent system of constant rigidity that is solved by linear analysis.The numerical results compared very well with those of the experimental ones. The proposed concept is found to be computationally more efficient and simpler to model compared to FEM for solving similar thermo-elasto-plastic nonlinear problems. The procedure presented in this work and the results thus obtained, holds a great promise for determining the heat sinking parameters for effectively controlling welding distortion.

Collapse Strength of Intact Ship Structures

“…More complex cases have also been studied, including multi-pass welding [59] and the effect of the sequence in multiple welding [60]. Proper sequences are chosen to reduce the weld induced distortions, but restraining the plate during welding is another approach adopted and studied [61][62][63][64][65].…”

Thermal and structural modelling of arc welding processes: A literature review

“…Both experimental and numerical work was done and compared in which good agreement was obtained. 34 Predicting the welding residual stress in GMAW process, a neural-network model was developed. The input welding process parameters and geometrical parameters were taken and the residual stresses were studied.…”

“…Welding stresses originate from the restrained welding distortion. Many research papers 24–51 describe the models used to find the welding distortion and welding residual stresses. To get the exact model, the field describes the specimen of metal needed to be able to change its volume and shape; along with this, properties of the materials are required like specific heat, plasticity, Poisson’s ratio and density.…”

Evaluation of Welding Distortion and Hardness in the A36 Steel Plate Joints Using Different Cooling Media

“…The investigation was conducted through the concept of pseudo linear equivalent stiffness, which is normally used to simultaneously analyze the thermo-mechanical object welded with heat sinking. This means it is possible to overcome the welding distortion by modeling the nonlinear thermoelastic-plastic using the finite element method [3]. Furthermore, low-carbon steel buttwelded joints were also investigated using the thermo-elastic-plastic FEM method, and its ability to predict weld distortion was confirmed by experimental results [4].…”