Structural Behavior Of Advanced High Strength Steel: Ductility, Connections, Members

Abstract

This paper summarizes recently completed experimental and numerical research on the structural behavior of advanced high strength steel (AHSS) structural components conducted at the authors’ institutions. For material ductility, tensile coupon tests were completed to establish a database of the stress-strain curves for these new materials and also to develop quantifications of their ductility. The research on connections focuses on the strength of four cold-formed steel (CFS) connection limit states: tension rupture, bearing, tilting/bearing, and end tear-out. The relationship between connection strengths and material ductility is investigated to further the understanding of ductility demand in CFS connections. Research on AHSS structural members includes columns in pure compression and beam in major axis bending. Analysis of the member experiment and finite element simulation results lead to proposed improvements for the Direct Strength Method (DSM) in members with high slenderness and/or high mode interaction potential. Overall, the study reported in this paper improves the understanding of ductility’s influence in structural connection design and extends the applicability of the current CFS buckling design method for high slenderness members, all of which make necessary preparations for introducing this new type of high-strength steel, AHSS, into cold-formed steel design specifications and more broadly in building construction.