Influence of steel strength and loading mode on fatigue properties of resistance spot welded H section specimen

Abstract

The drive to reduce vehicle mass by substituting mild steel with thinner high strength steel means that design engineers are now working closer to the design limits with respect to the fatigue performance of spot welded structures. Consequently, the present study was initiated to evaluate the factors that influence the fatigue performance of spot welded H sections so as to optimise the performance of spot welded high strength steel structures. The results obtained indicated that steel strength had little effect on fatigue performance while, in contrast, the loading mode, weld size and sheet thickness had a significant influence on it. The results of shear loading were up to 10 times greater compared with that under peel loading conditions. Under shear loading conditions full plug failures were noted, whereas with peel loaded variants partial plug failures predominated. With respect to enhancing the fatigue properties the use of larger weld sizes was shown to be beneficial.

Keywords

SHEAR H SECTION PEEL H SECTION SPOT WELDING FATIGUE PERFORMANCE AUTOMOTIVE DURABILITY LOADING MODE FAILURE MODES

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