Experimental investigation and predictive models of membrane residual stresses in S690 high strength steel welded n-shaped and cruciform sections

This paper reports an experimental investigation of the membrane residual stresses in S690 high strength steel welded n-shaped and cruciform sections. The experimental programme was performed on three n-shaped sections and two cruciform sections, fabricated from 5 mm thick S700MC high strength steel plates by means of gas metal arc welding, and included material tensile coupon tests and membrane residual stress measurements, with two measurements for each of the five S690 high strength steel welded n-shaped and cruciform sections. The measured tensile and compressive membrane residual stresses were analysed and the self-equilibrium of the measured membrane residual stresses in each constituent plate element was also verified, with the maximum unbalanced membrane residual stress to yield stress ratios of 3.3% for n-shaped sections and 3.2% for cruciform sections. The existing membrane residual stress predictive models, as given in the European convention and Swedish regulations, were assessed for their applicability to S690 high strength steel welded n-shaped and cruciform sections, revealing inaccuracy. Finally, two sets of new predictive models for membrane residual stresses in S690 high strength steel welded n-shaped and cruciform sections were proposed and shown to result in accurate predictions of the measured membrane residual stress data.