G0301106 A Method for Calculating Nominal Structural Stress of Spot-welded Structure (Study of spot weld FE model other than evaluation point)

Abstract

In one of the spot welded structure fatigue life prediction method, there is a method of using the nominal structural stress of the spot welding as the evaluation parameter. The nominal structural stress calculation method can obtain the nominal structural stress accuracy by using the general loads and the displacements in the vicinity of nugget. The FE model of spot weld is made as the octagon model that consists of the beam element and 8 rigid bar elements. However, it is not easy to apply this octagon model to the entire structure. In this study, the spot weld FE models other than an evaluation point were made as a simple model, and the accuracy of stress solution that was obtained from nominal structural stress calculation method was studied. As a result, it was shown that the nominal structural stress was accurately obtained by using the cross model that consists of the beam element and 4 rigid bar elements.