无预紧力变摩擦阻尼器的研发与 简谐激励下的动力特性分

Friction damper belongs to displacement dependent damper, which has the characteristics of simple structure, strong energy dissipation and stable performance. It has been used in many projects over the years. Based on the amplification mechanism of ball screw pair, a non-preload variable friction damper was proposed in this paper. The structure and action mechanism of the device were introduced. The restoring force model was given according to the restoring force formula. The correctness of NVFD action mechanism and restoring force model was verified by quasi-static test. Finally, the displacement analytical solution and dynamic amplification factor of NVFD single degree of freedom damping system under simple harmonic load were derived, and the relevant parameters were analyzed. The results show that; as long as NVFD parameter is reasonable and in sliding state under external excitation, the analytical solution and numerical solution basically agree, and the analytical solution derived by harmonic balance method has high precision. When the frequency ratio is less than 1.5, the dynamic amplification coefficient of NVFD decreases with the increase of spring stiffness and friction magnification, and is not affected by the mass change of the circular steel plate.