Thermo-mechanical Analysis of Welding Distortion Control through Heat Sinking using Pseudolinear Equivalent Constant Rigidity Concept

摘要

Since arc welding is a transient thermal process, it leads to a time varying temperature field all over the plates being welded. This in turn may cause residual deformations in the plates. Theoretical evaluation of deformation due to the thermal cycles necessitates the solution of a complex time dependent thermal elasto-plastic problem. Solving such problems analytically is not always feasible. However, conventional numerical techniques prove to be highly time consuming and it therefore becomes prohibitively expensive handling big and somewhat complex structures. The pseudolinear equivalent constant rigidity concept has been developed in this investigation for thermo-mechanical analysis of plates undergoing welding. The initial nonlinear problem, with modulus varying with temperature, was transformed into a pseudolinear equivalent system of constant rigidity that was solved by linear analysis. The numerical results compared very well with those of the experimental ones. The proposed concept was found to be computationally efficient and simpler to model than FEM for solving similar thermo-elasto-plastic nonlinear problems. Subsequently this technique has been extended to analyze a case of heat sinking for controlling deformation. The procedure presented in this work and the results thus obtained hold great promise for determining the heat sinking parameters for effective control of welding distortion.