Based on the passive control theory

this article presents a new type of metal variable friction damper which depends on energy dissipation.By changing the friction area of metal friction surface

the friction coefficient varies with the change of displacement.On the basis of the theory of metal tribology

we establish damping force calculation model and product development for metal variable friction dampers.Theoretical calculation results and experimental data show that the damping performance of the new metal variable friction damper is significantly better than that of conventional dampers.The proposed damper avoids the defects of the traditional damping devices

such as those of oil dampers: high cost

complicated maintenance and easy spilling.It also overcomes the problem that conventional friction dampers cannot maintain the same control effect in different sizes and loads.The new metal variable friction damper maintains excellent anti-seismic effect under different loads

i.e.less energy consumption and smaller displacement in small earthquakes

while more energy consumption and larger displacement in heavy earthquakes.