Numerical Analysis of Welding Residual Stress in Laser+MIG Hybrid Butt Welding of Medium-thick Aluminum Alloy

doi:10.3901/JME.2018.02.077

Abstract

Abstract: Based on thermal-elastic-plastic theory, a three dimensional numerical model of residual stress in laser+metal inert gas (MIG) hybrid welding of aluminum alloy is developed. The laser and arc heat inputs are modeled as the double ellipsoid heat source and the cone heat source with exponentially enhanced power density along the central axis, respectively. Using the built model, the residual stress in hybrid butt welding of 12 mm thick aluminum alloy is calculated through ANSYS finite element software and its distribution feature is analyzed, which is also compared with that of MIG welding. The calculated results of temperature and residual stress fields are compared with the experimental data to validate the accuracy of the model. Results show that, in and near weld zone, both the longitudinal tensile stress and Von-Mises equivalent stress are higher, their peak values being lower than the yielding stress of base metal. In addition, the stress in laser action zone is larger than that in arc action domain. A transversal tensile stress is generated at weld toe but its peak value is small. Compared with those of multi-pass and multi-layer MIG welding, the high stress is narrower. The peak stress at top surface of workpiece in hybrid welding is lower than that in MIG welding. But, at the workpiece bottom surface, the former is greater than the latter.

Key words: aluminum alloy, hybrid welding, numerical simulation, residual stress

CLC Number:

TG456

XU Guoxiang, GUO Qinghu, HU Qingxian, ZHU Jie, LIU Peng, PAN Haichao. Numerical Analysis of Welding Residual Stress in Laser+MIG Hybrid Butt Welding of Medium-thick Aluminum Alloy[J]. Journal of Mechanical Engineering, 2018, 54(2): 77-83.

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