TY - GEN
T1 - Modeling of transport phenomena and thermal stress in spot laser keyhole welding
AU - Zhou, Jun
AU - Khalilollahli, Amir
AU - Tsai, Hai Lung
PY - 2011
Y1 - 2011
N2 - Due to the highly-localized heating and non-uniform cooling in spot laser keyhole welding, complex residual stresses are often found in final welds, which can cause detrimental effects on mechanical properties of the welds and result in problems like cracking and distortion. Since the formation of thermal stress is tightly related with the heating, melting, solidification, and cooling processes in welding, accurate analysis of the transient thermal transport phenomenon in welding is critical to predict the thermal stress information in final welds. In this study, a comprehensive thermal model analyzing the heating, melting, solidification, cooling processes in spot laser keyhole welding is integrated with a mechanical model to accurately predict the thermal stress evolutions in laser welding and the resultant residual stresses in final welds as well. High compressive residual stress was found on the top surface of the workpiece in welding which causes rough surface (bumps) of the final weld. Residual tensile stress in some locations in the final weld was found to be higher than the critical level which indicates the potential thermal cracking occurrence. The proposed models can be used to further study the thermal stress formation mechanisms in laser welding and to provide a cost-efficient way to optimize the welding operations.
AB - Due to the highly-localized heating and non-uniform cooling in spot laser keyhole welding, complex residual stresses are often found in final welds, which can cause detrimental effects on mechanical properties of the welds and result in problems like cracking and distortion. Since the formation of thermal stress is tightly related with the heating, melting, solidification, and cooling processes in welding, accurate analysis of the transient thermal transport phenomenon in welding is critical to predict the thermal stress information in final welds. In this study, a comprehensive thermal model analyzing the heating, melting, solidification, cooling processes in spot laser keyhole welding is integrated with a mechanical model to accurately predict the thermal stress evolutions in laser welding and the resultant residual stresses in final welds as well. High compressive residual stress was found on the top surface of the workpiece in welding which causes rough surface (bumps) of the final weld. Residual tensile stress in some locations in the final weld was found to be higher than the critical level which indicates the potential thermal cracking occurrence. The proposed models can be used to further study the thermal stress formation mechanisms in laser welding and to provide a cost-efficient way to optimize the welding operations.
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M3 - Conference contribution
AN - SCOPUS:80455141625
SN - 9781618390578
T3 - Transactions of the North American Manufacturing Research Institution of SME
SP - 546
EP - 552
BT - 39th North American Manufacturing Research Conference 2011 - Transactions of the North American Manufacturing Research Institution of SME
T2 - 39th Annual North American Manufacturing Research Conference, NAMRC39
Y2 - 13 June 2011 through 17 June 2011
ER -