Experimental and modeling study of high-strength structural steel under cyclic loading

In order to study cyclic performance of high-strength structural steel and establish an appropriate constitutive relationship, experiments were carried out on seventeen Q460D steel specimens subjected to different loading patterns. The mechanical responses of high-strength structural steel were evaluated and discussed including stress–strain relationship, failure modes, ductility and hysteretic performance. A constitutive model was further established for uniaxial cyclic loading and implemented in ABAQUS through its user subroutine interface – UMAT. After justification of the modeling results by the experimental measurements from various loading conditions, the proposed model was applied in nonlinear time history analysis for steel frames using fiber beam element method. Both experimental and modeling results showed that the responses of high-strength structural steel under cyclic loading and monotonic loading were different and the necking and fracture behavior would occur in advance for the former because the accumulated damages reduced the ductility of steel.