Application Research Of Beam String Structure With Uplift Resistance Triple Friction Pendulum Isolation Bearing

As a kind of natural disaster,the earthquake has brought incalculable harm to human time and again in the history of human development,but until now the human still can not find effective ways to prevent or avoid the occurrence of the earthquake.Many buildings which are designed based on traditional earthquake-resistant design can not withstand violent earthquakes and collapse,resulting huge losses to the country and its people.And those buildings become "standing remains" because their building structures are badly damaged though they do not collapse.The ductility of the traditional design method depends on the damage of structure to absorb the energy of the earthquake,that is,the ductility is damage,however after the earthquake,the paralysis of hospitals,command center and transportation hub will cause a greater disaster.Seismic isolation technology has changed the situation,different from the traditional seismic method,it sets up seismic isolation bearings between the foundation and upper structure,isolates the upper structure and foundation,as a result,it lengthens of the natural period of vibration,avoids predominant period of ground motion,and reduces the seismic response of the upper structure.But the traditional seismic isolation bearings do not have the ability to resist pulling,so its application in the large-span space structure is limited.To better study the uplift resistance triple friction pendulum isolation bearing,first,theoretical analysis and numerical simulation are carried out on friction pendulum isolation bearing,and experimental research is conducted on the friction pendulum isolation bearings to probe into its hysteretic property as well as the factors affecting the friction coefficient of friction material,then theoretical analysis and numerical simulation are carried out on double concave friction pendulum isolation bearing and triple friction pendulum isolation bearing,based on this,along with principle of equilibrium in mechanics,theoretical derivation on uplift resistance triple friction pendulum isolation bearing has been achieved.And based on ABAQUS,finite elaborate meta models of isolation bearings are built to explore the hysteretic property.Finally,uplift resistance triple friction pendulum isolation bearing is used in beam string structure to study its isolation performance.Results show that using isolation bearing effectively prolongs the fundamental period of beam string structure,due to the setting of the tension spring makingcontributions to the stiffness of the isolation layer,so compared with traditional friction pendulum isolation bearings of the same size,uplift resistance triple friction pendulum isolation bearing has a shorter isolation period under the same working condition,but it still has the very good isolating effect;by setting uplift resistance triple friction pendulum isolation bearing,the axial force peaks of beam string structure given by the bar are decreased and upper chord damping coefficient of the beam string structure shift from the edge to the center,presenting a rule of first increases and then decreases;while the lower chord damping coefficient becomes larger as it comes near the center of the structure;Vertical web member damping coefficient becomes smaller as it comes near the center of the structure;due to setting uplift resistance triple friction pendulum isolation bearing,column feet counterforce can be reduced,servicing as a protective role.Results obtained from this thesis will offer some reference to further research and application in engineering concerned with uplift resistance triple friction pendulum isolation bearing.