ABSTRACT
High-Strength Steel (HSS) is gaining widespread acceptance in contemporary engineering structures, with grades of up to 690 MPa being included in many design standards. Strength grades well in excess of 690 MPa are possible with modern metallurgical process, but they are not compliant with most design codes of practice. HSS is advantageous when the structural performance is dominated by strength rather than stiffness, in which case it is very useful in reducing the self-weight of the structure. The lateral buckling resistance of steel members depends on the interaction of elastic buckling, yielding and post-yielding and of residual stresses. Current design practice is based on stress-strain laws and residual stresses for mild steel and it is not established that the design provisions for mild steel are applicable for HSS. This paper presents an investigation of the lateral buckling strength of HSS beams using ABAQUS, incorporating stress-strain curves and residual stresses reported in the literature. With a similar methodology to mild steel members, the interaction of elastic buckling at the member scale with the material characteristics at the cross-section scale is investigated and a strength design formulation is proposed.
