Friction Damper Development And Application

As the friction damper has a simple structure, perfect energy dissipation capacity, not Affect by the frequency of the load,it has been widely used in Construction. Conventional friction damper often only has a single sliding force, very difficult to take into account both medium earthquake’s performance requirements and large earthquake’s performance requirements. This paper describes a new type of variable friction damper. It makes the semi-active control of friction damper come true by its unique " spring-slope " institutional.Existing friction damper has many Defects such as the output is small and inadequate, poor durability Etc. this paper, introduce the development goals of new friction damper with combineing realization, include durability, variable friction, large output and so on. Originality put forward a" spring-slope " prototype device. The device can made the friction be proportional to the deformation by adjusting the slope angle and the spring stiffness, ie realized the variable friction semi-active control effects.Using the "spring-slope" prototype device, designed a "flat" type variable friction damper,"friction hinge" type variable friction damper," sleeve barrel brace" type variable friction damper, and " scissile bond" variable friction dampers, according to the specific needs of different projects. deduce the theory output formula of the variable friction damper using "spring-slope" device as the prototype. the variable friction dampers mentioned above can present Triangle hysteretic curve Or "dog bone-shaped" hysteresis curve by adjusting the slope section and the ratio of section plane. The "dog bone-shaped" hysteresis curve make an improvement on weakness of the single sliding force of the traditional friction damper. using the disc springs reduced the effect of creep relaxation of the bolt to the preload, setting slope section would make the sliding force be lower,with the energy dissipation capacity the same, thus reduced preload, reduced bolt relaxation, so would ensure the damper durability.In this paper, variable friction damper plate experimental study of specimens, including the incremental displacement hysteresis loops,the maximum deformation of the hysteresis loop experiments, different sliding force hysteretic behavior experiments, Etc.. compare The experimental results and theoretical analysis, the experimental results are basically consistent with the theoretical solution, the paper also discussed the possible cause of the Error between the theoretical solution and the true solution. In order to improve the friction damper output, the friction materials always have to withstand high compression stress, to improve the performance of friction materials, proposed the way of "lattice", which made the friction material in a three-state pressure to improve the compressive performance of friction materials.This paper focuses on the numerical simulation analysis about the earthquake resistant performance of Variable friction damper with Triangular hysteresis curve and "dog bone-shaped" hysteresis curve. First studied the free vibration of a single-degree-of-freedom structure with triangle hysteresis curve element, Solving the Equivalent period,Equivalent damping ratio and other Performance parameters. Adding triangle hysteresis curve element to the structure, would make the structure’s Equivalent damping ratio will increase, maximum displacement will reduce. Structural stiffness varies with the structure deformation, Showed the characteristics of semi-active control. Second, numerical simulation analysis a single-degree-of-freedom structure with Triangular hysteresis curve element and "dog bone-shaped" hysteresis curve element Respectively. analyzed the inflection point of the hysteresis curves in the time-history analysis may encounter, and the treat method. Written programs for nonlinear dynamic time history analysis. Change the parameters of the hysteresis element, study the effect of various parameters to the damping effect. By analysis above, in small earthquake and medium earthquake, the damping effect of " dog bone-shaped" hysteresis element and rectangular hysteresis curve element are nearly the same, in the large earthquake," dog bone-shaped" hysteresis curve element has better damping effect. Adjust the "dog bone-shaped" hysteresis curve parameters appropriately, could take care of the small earthquake medium earthquake and large earthquake’s Damping requirements.