Development And Performance Study Of New Type Of High Damping Rubber Bearing

With the frequent occurrence of strong earthquakes in recent years,the demand for building high-damping isolation bearings is becoming more and more urgent.The excellent high-damping composite rubber material formula is the key to the preparation of high-damping isolation bearings.The domestic scholars' researches on composite materials are mostly based on mechanical vibration and noise reduction.However,there are few reports on the application of composite materials for building high-damping seismic isolation bearings.Therefore,high-damped seismic isolation bearing composite materials with excellent comprehensive performance for research and development have Far-reaching significance.In this paper,strong polar nitrile rubber(NBR)with good damping properties is selected as the matrix material,and the composite rubber material is prepared by adding organic small molecules,polar rubber,and resin blends,and a series of composite materials with excellent comprehensive properties are developed.The mechanical properties,damping properties and anti-aging stability of the composites were analyzed using universal testing machines and dynamic mechanical analyzers.Based on the experimental formula,three high-damping isolation bearings of the same specifications were prepared and tested.The main research contents and conclusions are as follows:(1)Binary composite systems NBR/AO-2246 and NBR/BIIR were prepared by blending small organic molecules AO-2246 and bromobutyl rubber(BIIR)with nitrile rubber respectively.The results show that NBR/AO-2246 composites not only have excellent mechanical properties,but also have higher damping peaks and controllable glass transition temperatures.NBR/BIIR composites have lower mechanical properties due to different cross-linking densities.With the increase of the proportion of BIIR,the effective temperature range of the composite material is continuously expanding.When the blend ratio NBR/BIIR is 30/70,the maximum effective temperature range is 85.60°C,but the damping value at the valley of the tan?-T curve is relatively Lower.Further aging tests show that the anti-aging stability of NBR/AO-2246 composites is poor.On the contrary,NBR/BIIR composites have good anti-aging stability and can be used as matrix materials for the preparation of compositematerials with high damping and wide temperature range.(2)The ternary composite systems NBR/BIIR/EVA and NBR/BIIR/CR were prepared on the basis of binary NBR/BIIR composites by adding EVA resin and chloroprene rubber(CR)with good compatibility,respectively.The research results show that the ternary composite system has excellent comprehensive mechanical properties and anti-aging stability.The effective temperature range of NBR/BIIR/EVA composites increased with the increase of EVA resin content,but the damping value at the troughs did not meet the requirement of "tan??0.3".With the increase of CR content in NBR/BIIR/CR composites,the effective temperature range was increased.The damping value at the wave trough increases continuously and then decreases.When the blending ratio NBR/BIIR/CR is 30/70/60,the damping value at the trough reaches a maximum of 0.68,and the effective temperature range is 102.96°C.The composite material has excellent properties.The overall performance.(3)Based on the experimental formulation of NBR/BIIR/CR composite materials,three high-damping isolation bearings with the same specifications were prepared and tested.The test content includes the rubber material test,the mechanical properties of the bearing and the correlation test.The results show that the mechanical properties of the high damping bearing are excellent,and it has better damping performance than the ordinary bearing.