Axial compression behaviors of steel shear-keyed tubular columns: Numerical and analytical studies

This study developed a finite element model (FEM) and reported parametric and analytical studies on the axial compression behaviors of shear-keyed tubular columns in modular steel structures (MSS). The accuracy of the developed FEM was validated using 36 tests in references. The parametric study designed 108 FEMs to inves-tigate initial imperfection, shear-key height (Lt), thickness (tt), steel tube length (D), width (B), thickness (tc), and height (Lc) influence. The typical load-shortening response showed elastic, inelastic, and recession stages, with failure modes of inward and outward sinusoidal pairs of local buckling. Increasing tt, Lt, tc, D, or B improved strength and stiffness, while Lc or slenderness (Lc/r) adversely affected the stiffness and ductility linearly. Besides, it ensured by validations that prediction equations in conventional design standards overestimated the compressive resistance, requiring modifications.