Mechanical characteristics of resistance multispot welded joints

Abstract

In the present study, three-dimensional thermal elastoplastic analysis has been carried out in order to clarify the mechanical phenomena of the thermal elastoplastic behaviour of multispot welded joints. As the shape of multispot welded joints is not axisymmetrical, unlike single spot welded joints, the solution domain for simulation should be three-dimensional. Therefore, the present study first developed three-dimensional heat conduction and thermal elastoplastic programs using the isoparametric finite element method. Second, from the results analysed by the developed programs, thermal and mechanical characteristics and their production mechanisms on single and multispot welded joints were clarified. Moreover, effects of pitch length on the temperature distribution, welding residual stresses and plastic strain of multispot welded joints were evaluated, indicating that a pitch of 30 mm was more advantageous compared to a pitch of 15 mm.