Multi-stage self-resetting buckling-restrained brace and energy dissipation method and application thereof

The invention relates to a multi-stage self-resetting buckling-restrained brace which comprises a middle positioning plate and two-stage buckling-restrained units located on the two sides, and the bearing capacity of the two-stage buckling-restrained unit on one side is larger than that of the two-stage buckling-restrained unit on the other side; each two-stage buckling-restrained unit comprises aconnecting joint, a supporting core component, an outer sleeve steel pipe, a sliding bearing plate, a fixed bearing plate, a stable steel bar, a steel frame support, a belleville spring and a friction plate. The invention further relates to an energy dissipation method of the multi-stage self-resetting buckling-restrained brace, energy is dissipated through the effects of the friction plates andthe stable steel bars, and energy is dissipated through the belleville springs. The self-resetting capability is provided through the belleville springs; the two-stage buckling-restrained unit with small bearing capacity serve