Experimental Study On Mechanical Properties Of Collecting Ball Vertical Isolation Tube

Earthquake,also known as earth moving,ground vibration,is a natural phenomenon that the process of earthcrust release energy rapidly results in vibration and produce seismic waves.Squeezed and collision between plate and plate of the earth’s result in the edge of the plate and plate internal produce dislocation and fracture,is the main cause of the earthquake.It is generally believed that the main cause of earthquake damage is the horizontal seismic action,the vertical seismic action is only equivalent to 1/3 to 1/2 of the horizontal seismic action.However,in the last few decades,a large number of seismic vertical acceleration components have been monitored many times in the high-intensity near-fault seismic area,and the peak value is even greater than the horizontal acceleration peak.Therefore,how to effectively carry out the vertical isolation has become a proposition to be resolved in isolated engineering industry.Based on the comprehensive understanding of vertical isolation and three-dimensional isolation at home and abroad,this paper combed the types,working principles,structures and the advantages and disadvantages of current vertical isolation system,and carries out and completed the following work:(1)Combined with the factors that reflected by vertical isolation theory and affect vertical isolation effects and the factor orthogonal test of small diameter 220 mm isolation cylinder,optimized the isolation cylinder,designed and made six kinds of collection ball vertical isolation tube including three types of diameter,two classes of height.(2)Based on the vertical mechanical performance test of six sets of collecting ball vertical isolation tubes,the effects of four factors,including rubber ball hardness and fill rates,load frequency,load times.related to the packing of the vibration isolator and the external input load on vertical stiffness and energy dissipation of collecting ball vertical isolation tube were studied.According to the test results,effects of various factors on the mechanical properties of the isolated tubes were analyzed.The test prove that the effects of loading frequency and loading times on isolation tubes can be ignored while rubber ball hardness and fill rates are positively associated with the average vertical stiffness of isolation tubes,and pure rubber ball diameter filling have limited effect on isolation tubes.(3)Through the vertical mechanical test,the vertical vibration law of different diameter and different height ball set vertical isolation tube,tube diameter and height of the isolation of different average vertical stiffness research and energy dissipation capacity,and isolation cylinder in compression height under the influence of surface pressure test results sorting and analysis,obtained as a single isolated cylinder variable in diameter or height,larger diameter tube,tube average vertical stiffness of isolation is greater;the height of the cylinder barrel,isolated average vertical stiffness is smaller;surface pressure can reach 5.5MPa ~ 6.5MPa ultimate bearing isolation cylinder in the working stroke range.It provides a reliable experimental data base for the establishment of the model of the vertical isolation cylinder.(4)A rubber bearing and the collecting ball vertical isolation tube series into a three-dimensional isolation bearing,then performance test of the three-dimensional isolation bearing is conducted through inputting loading plan with different amplitude and frequency to the three-dimensional isolation bearing.After that,this paper obtained the hysteresis curves of the three-dimensional isolation bearing,the collecting ball vertical isolation tube and the rubber bearing.After comparing the test results,the three-dimensional isolation and energy dissipation of the three-dimensional isolation bearing are further tested.(5)A computational model,double parabolic model,was presented.The mechanical property of collecting ball vertical isolation tubes was fitted.The influence factors and model parameters were quantified which provides a set of calculation model of mechanical properties of collecting ball vertical isolation tubes.Finally,the above research results are briefly summarized and the direction of further research and the work to be done were pointed out.