Nonlinear finite element modeling of two-stage energy dissipation device with low-yield-point steel

Equipped with many advantages, such as low yield strength, low yield ratio, high elongation, severe plastic deformation and good energy dissipation ability, low-yield-point steel is very suitable for use in metal energy dissipation devices. Based on different materials (Q235 steel and low-yield-point steel) and different parabola openings, two types of energy dissipation steel plates underwent different yield displacements and then were assembled into a new open-hole energy dissipation device, which could achieve the goal of two-stage energy dissipation under small and large earthquakes. To obtain the failure modes and energy dissipation mechanism under the low reversed cyclic horizontal loads and observe relevant hysteretic curves and skeleton curves, the new energy dissipation device was studied and analyzed by means of theoretical analysis, experimental research, and numerical simulation analysis. Based on parametric analyses, the effects of the height, thickness and opening coefficient of the steel plate on the energy dissipation ability of the new energy dissipation device were emphasized. Thus, the key parameters affecting the energy dissipation behavior were obtained. Finally, a force-restoring model of the new energy dissipation device was put forward, and the calculation formulas were given for many parameters, including stiffness, yield displacement, yield load, ultimate displacement and ultimate load. The results show that the new open-hole energy dissipation device has the advantages of superior energy dissipation performance, obvious energy dissipation in two stages, and wide application prospects in structural seismic design.