LOCAL STRESS PARAMETERS AT THE WELD SPOT OF VARIOUS SPECIMENS

The strength of spot welded joints is assessed by analysing the local stress parameters at the edge of the weld spot, the hot spot structural stress, the notch stress and the stress intensity. The latter are determined by means of finite element and boundary element calculations as well as by means of novel formulae for the relation between structural stress and stress intensity for common single and multiple spot specimens when the weld spots are subject to shear and cross tension loading. From this is derived the relation of the likely load bearing capacity of the weld spots in the various specimens and load cases. This also comprises a design evaluation. Finally, the effect of a variation in plate thickness and weld spot diameter on the load bearing capacity is presented by taking the example of the tensile shear and cross tension specimen.