Study On Mechanical Properties Of A New Type Of Vibration Reduction And Self Reduction Auxiliary Structure In Bridge Application

NSD is a new type of negative stiffness damping mechanism,that is,under the displacement excitation,it can produce the force which is consistent with the displacement direction.The existing series of studies show that NSD has better damping effects and self reset function,and NSD mechanism is structural damping passive control technology without external energy input,which completely based on the mechanics of negative stiffness so as to achieve the effect of damping.As a passive energy dissipation device,NSD can eliminate the influence of the input and output of the active and semi-active control devices to a certain extent.At present,the research results of energy dissipation capacity based on NSD are few.Therefore,it is urgent to analyze the seismic mechanism of the improved self reduction negative stiffness mechanism.In order to further improve the seismic performance of the existing negative stiffness device(NSD),modified negative stiffness devices(MNSD)was developed with supplemental energy-dissipation component installed in parallel to pre-compressed spring to enhance its energy-dissipation capacity.Design parameters as stiffness and prescribed pre-compressed displacement of pre-compressed spring were taken into account to design 5 full-scale specimens,and the commercial FE software ABAQUS was adopted to simulate their seismic mechanism under lateral low-cycle reversed loading.Based on the analysis data,the specimen's performance were analyzed,including hysteretic characteristics,lateral resisting stiffness and energy-dissipation.In order to verify structural damping effects of the modified negative stiffness devices,this paper designed the straight column pier structure built-in modified negative stiffness devices as an example,and using the commercial FE software ABAQUS on the level of lateral low-cycle reversed loading and unidirectional loading under the numerical simulation.The results indicated that the stiffness and prescribed pre-compressed displacement of pre-compressed spring both effect the process of weakening the structure to reduce the seismic response,while the stiffness of pre-compressed spring also effect the function of strengthening and self-centering of structure after decompression of pre-compressed spring;supplemental energy-dissipation component can provide energy-dissipation capacity for the structure to further reduce the seismic response,correspondingly MNSD can meet the performance design target of seismic response reduction,energy dissipation capacity and self-centering.