Inelastic Buckling Simulation of Steel Braces through Explicit Dynamic Analyses

This paper presents a veritable finite element approach for simulating the inelastic buckling response of steel braces. A number of techniques are considered to identify computationally efficient modeling approaches that yield consistent results with experimental data. Ultimately, brace members and gusset plates are represented with deformable and rigid shell elements, respectively; and the overall method is based on dynamic analyses with explicit time integration. There is inherent damping in the proposed model due to inelasticity; additional viscous damping and mass scaling factors are used to extract/simulate the system's quasi-static responses. Static sensitivity analyses are conducted to optimize mesh sizes and the most suitable imperfection shapes and amplitudes for the brace elements. Additional (dynamic) sensitivity analyses are employed to calibrate the imperfection, loading amplitude, time period, artificial viscous damping and mass scaling factors. Results indicate that the proposed techniques can accurately mimic experimentally observed quasi-static responses.