Influence of Welding Parameters on the Spot Weld Torsion Test on a Newly Developed Automated Device

Abstract

The main process of joining plates in vehicles is Resistance Spot Welding. When in work the spot weld of the vehicle structure suffer tensile, shear and torsional stresses having less resistance to torsion. The correct characterization of the strength of the welded joint is of extreme importance to guarantee the safety of the vehicle. It is fundamental knowing the reaction to the efforts for the correct design of the point. For strength and shear stress, tests are used with known failure mode and relationship between parameters and stresses. For the torsion test, automated, compact and simple handling equipment has recently been proposed. Therefore, the objective of this work is evaluate the influence of the parameters: time and welding current in the test result. It was welded with specimens of 0.91mm thickness, maintaining the current at 4.25kA, 5.0kA and 5.75kA and varying the welding time at 10, 30, 50, 70 and 90 cycles. The tests showed a great influence of the welding current on the torsion test characteristic curve, a phenomenon that was not repeated for the welding time.

Key-words:
Spot welding; Torsion resistance; Welding parameters