Influences of Weld Nugget Shape and Material Gradient on the Shear Strength of Resistance Spot-Welded Joints

作     者：Schuster, Lilia Olfert, Viktoria Sherepenko, Oleksii Fehrenbach, Clemens Song, Shiyuan Hein, David Meschut, Gerson Biro, Elliot Muenstermann, Sebastian 

作者机构：Fraunhofer Inst Mech Mat IWM Component Safety & Lightweight Construct Wohlerstr 11 D-79108 Freiburg Germany Univ Paderborn Lab Mat & Joining Technol LWF Pohlweg 47-49 D-33098 Paderborn Germany Univ Waterloo Dept Mech & Mechatron Engn 200 Univ Ave WestE3 3101D Waterloo ON Canada Rhein Westfal TH Aachen IEHK Steel Inst Intzestr 1 D-52072 Aachen Germany 

出 版 物：《STEEL RESEARCH INTERNATIONAL》 (Steel Res. Int.)

年 卷 期：2024年第95卷第4期

核心收录：

学科分类：080602[工学-钢铁冶金] 0806[工学-冶金工程] 08[工学] 

基　　金：Research Association for Steel Application (FOSTA) Research Association for Steel Application (FOSTA), Dusseldorf - Federal Ministry of Economic Affairs and Climate Action the German Federation of Industrial Research Associations (AiF) [IFG 20998 N/P 1431] 

主　　题：advanced high-strength steels finite-element methods resistance spot welding three-sheet joints total dome failures 

摘      要：Resistance spot-welded joints containing press-hardened steels are seen to exhibit a fracture mode called total dome failure, where the weld nugget completely separates from one steel sheet along the weld nugget edge. The effect of weld nugget shape and material property gradients is studied based on damage mechanics modeling and experimental validation to shed light on the underlying influencing factors. For a three-steel-sheet spot-welded joint combining DP600 (1.5 mm)-CR1900T (1.0 mm)-CR1900T (1.0 mm), experiments under shear loading reveal that fracture occurs in the DP600 sheet along the weld nugget edge. In subsequent numerical simulation studies with damage mechanics models whose parameters are independently calibrated for every involved material configuration, three variations of the geometrical joint configuration are considered-an approximation of the real joint, one variation with a steeper weld nugget shape, and one variation with a less pronounced gradient between weld nugget material and heat-affected zone material properties. The results of the finite-element simulations show that a shallower weld nugget and a more pronounced material gradient lead to a faster increase of plastic strain at the edge of the weld nugget and promote the occurrence of total dome failure. Total dome failure is a fracture mode of resistance spot-welded joints, where the weld nugget completely separates from one steel sheet along the weld nugget edge. This study looks at the role of weld nugget shape and material gradient in the occurrence of total dome failure by means of finite-element *** (c) 2024 WILEY-VCH GmbH