Numerical modelling of residual stress redistribution induced by TIG-dressing

Abstract

TIG-dressing is a technique used to improve the fatigue strength of welded joints by a remelting of the weld toe region that promotes both a smoother transition between the plate and the weld crown and a residual stress redistribution. These effects are very hard to be quantified by numerical simulation since a highly coupled thermo-fluid-mechanical analysis is required. However, if the final weld toe geometry is supposed to be known or a-posteriori measured, a simplified numerical method can be used to simulate the residual stress redistribution that uses the activation-deactivation function of elements. This technique is applied to a real steel weldment and the results, in terms of phases proportions and residual stress redistribution, were found in good agreement both with data coming from metallurgical analysis and the improved fatigue strength observed on welded joints after the TIG-dressing operation.

An efficient model for the TIG‐dressing process numerical simulation

“…Thermo‐metallurgical and mechanical properties as a function of temperature of both filler and parent metals were taken into account. In particular, thermal and metallurgical properties were calibrated by experiments, while the mechanical properties as a function of temperature and phases were supposed equal to those of the ASTM SA 516 carbon steel The molten‐remolten effect was simulated by incorporating a function that clears the history of an element once the temperature exceeds the melting temperature.…”

“…The weld bead geometrical variation induced by re‐melting is influenced by the weldment distortions during TIG‐dressing and vice versa. For this reason, a numerical model of the TIG‐dressing process that simplifies a lot the computation by using the activation‐deactivation function of elements was recently published in literature . In this way, it is possible to avoid the fluid analysis, but the weld toe geometrical variation has to be a priori known by means of welding and TIG‐dressing trials.…”

Investigation of the Residual Stress in a Multi-Pass T-Welded Joint Using Low Transformation Temperature Welding Wire

“…Generally, tensile residual stress is detrimental to the fatigue strength, corrosion resistance and crack resistance of welded joints [ 2 , 3 , 4 ]. In order to minimize these adverse effects, it is necessary to take appropriate measures, such as ultrasonic peening [ 5 ], TIG dressing [ 6 ], local heat treatment [ 7 ] and so on. Nevertheless, these post-weld treatments are costly and time consuming.…”

The effect of nonlinearity of acceleration histories to timber beam seismic response

“…The stress, strain, displacement, strength, fatigue, stiffness, geometry, crack paths, two cross-section interaction, uniaxial loading, multiaxial loading, material characteristics, and embedded footings that have been investigated and reported in the literature are directly and indirectly related to strain energy dissipation and damping of the material, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] all of these concepts are required to apply on strain displacement of timber structure to enhance seismic design.…”