Effects of thermal transport in computation of welding residual stress and distortion

Abstract

The effects of considering thermal transport in weld modelling of residual stress and distortion are evaluated by performing a thermal transport analysis first to compute the temperature history which is then used as loading in a conventional elastoplastic analysis to compute the residual stress. A gas metal arc welding (GMAW) and a hybrid GMAW/laser welding case are used as examples. For each weld, residual stresses are computed once assuming conductive heat transfer only and once assuming convective (thermal transport) heat transfer. For GMAW welding, both heat conduction and thermal transport analyses produced similar temperature, residual stress and distortion results, indicating that heat conduction modelling with the double ellipsoid model may be sufficient for modelling GMAW. For hybrid welding, the heat conduction and thermal transport analyses produced different temperature histories and distortion results, demonstrating the need for including thermal transport effects in modelling keyhole welding. However, the residual stress results were in close agreement, suggesting that heat conduction analyses may be sufficiently accurate for computing residual stress even in keyhole welding.

Modelling welding residual stress and distortion: Current and future research trends

“…38, a simplified approach has been implemented to evaluate the effects of thermal transport in the residual stress computation. A thermal transport analysis is performed first to compute the temperature history which is then used as loading in a conventional elastoplastic analysis to compute the residual stress.…”

“…Typically, for problems exhibiting very large deformations an arbitrary Lagrangian-Eulerian (ALE) approach is used instead of a pure Lagrangian to minimise the error caused by the mesh distortion. [52][53][54][55][56][57] An advantage of ALE approaches for modelling FSW is the capability to model transient effects, tool plunge and tool removal and tool a heat conduction only; b thermal transport 1 Hybrid weld plate deformation magnitude (mm, 610) 38 Michaleris Modelling welding residual stress and distortion contact with the material. However, all current ALE models of FSW require adaptive remeshing that over time introduces numerical errors.…”

Imperfections generation in finite element models of welding

“…A weld-induced buckling is caused by the longitudinal stresses, originated in the welding process. Prediction of weld-induced buckling can be found in [30][31][32][33][34]. As known, a transient thermal structural welding simulation can produce an imperfection to the model for buckling.…”

Modeling of Gas Metal Arc Welding Process Using an Analytically Determined Volumetric Heat Source

“…[8][9][10][11][12][13]18) The conduction heat transfer based models for GMAW and SAW processes have also remained an effective recourse because of their computational simplicity, flexibility to consider wide-ranging weld joint geometry, and quick adoptability in several numerical analysis software that are widely available. [5][6][7][14][15][16][17] In contrast, the analytical heat transfer models to simulate GMAW process could consider simple joint geometry and constant material properties that usually inhibited accurate prediction of temperature field within the weld pool. 19,20) The majority of the conduction heat transfer based numerical models considered a volumetric heat source to account for the transfer of arc energy in the weld pool and, the heat source dimensions are determined either arbitrarily or based on the measured final weld dimensions that had restricted the predictive capability of these models.…”

“…[1][2][3][4] Although several efforts are published to simulate autogenous fusion welding processes, similar models that can also consider the electrode deposition such as in gas metal arc welding process (GMAW) and submerged arc welding (SAW) are only a few. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] The convective heat transport based have remained as a route to realize heat transfer and fluid flow in weld pool, and the resulting weld pool profile. [8][9][10][11][12][13]18) The conduction heat transfer based models for GMAW and SAW processes have also remained an effective recourse because of their computational simplicity, flexibility to consider wide-ranging weld joint geometry, and quick adoptability in several numerical analysis software that are widely available.…”