Multistage self-recovery type energy dissipation support and energy dissipation method thereof

The invention relates to a multistage self-recovery type energy dissipation support, and belongs to the technical field of engineering energy dissipation and shock absorption structures. The multistage self-recovery type energy dissipation support comprises a middle positioning plate and two second-stage buckling-restrained units located on the two sides and different in bearing capacity. Each secondary buckling-restrained unit comprises a connecting joint, a supporting core part, an outer sleeve steel pipe, a sliding bearing plate, an energy dissipation steel bar, a fixed bearing plate, a steel frame support, a shape memory alloy bar and a limiting block. The inner ends of the outer sleeve steel pipes are fixed with the middle positioning plate; the connecting joints, the supporting coreparts, the sliding bearing plates, the energy dissipation steel bars, the fixed bearing plates, the steel frame supports and the middle positioning plate are sequentially connected from outside to inside. Limiting blocks for