Damage And Protection Analysis Of Lead Rubber Bearings Under High Temperature

Fire not only changed the history of mankind,innovated new tools and technologies,but also changed human evolution.Fire is a double-edged sword.While it allows us to enjoy life and experience civilization,it also hurts us,causing serious losses to human life,property,and security.In fire accidents,the probability of building fire accidents is increasing.Since the Wenchuan earthquake occurred in 2008,due to the good performance of the isolated structure in the earthquake,people have paid more and more attention to it.It has also made the isolated structure widely used in major projects such as hospitals,schools,and stations,and has increased.The probability of an accidental fire in an isolated structure.However,since most of the vibration-isolating bearings are arranged on the top of foundation columns or walls usually in the basement,when a fire occurs,the vibration-isolating rubber bearings are directly exposed to the source of fire,giving the vibration-isolating rubber bearings and vibration-proof structures There are great potential safety hazards.Therefore,it is necessary to actively conduct research on the fire resistance of isolated rubber bearings.For the isolated rubber lead bearing,the laminated rubber material used is a super-elastic material.Unlike linear materials,the material characteristics and geometric characteristics of the rubber material show non-linear characteristics.The constitutive relationship of the rubber material and its strain energy Function related.According to the different constitutive models of rubber,according to the experimental data of the basic mechanical properties of rubber materials,the parameters of different rubber constitutive models are fitted using the material evaluation function in ABAQUS software.The performance indexes of different rubber constitutive models at different temperatures were investigated,which provided a basis for determining the superelastic constitutive model suitable for vibration-isolating rubber bearings.Based on the parameters of the isolated rubber lead support used in actual engineering,the ABAQUS finite element software is used to establish a numerical model of equal proportions,and the transient heat conduction and fire analysis of the isolated rubber lead support under the standard temperature rise curve is performed.The temperature field distribution of the numerical model is compared with the results of the support fire test,which verifies the correctness of the numerical model.At the same time,basic mechanical performance loading simulations of isolated rubber lead bearings at different temperatures were performed,and the mechanical properties and damage of the isolated rubber lead bearings at different temperatures were investigateIn view of the fact that the isolated rubber lead bearing has a certain degree of fire resistance in a short period of time,but the resistance to long-term fire is poor,this paper establishes four numerical models of fire protection for the isolated rubber lead bearing.Fourdifferent types of fire protection supports were subjected to transient heat conduction and fire simulation,and the basic mechanical performance tests of each model at different temperatures were simulated.The temperature field distribution and mechanical properties of each model at different temperatures were investigated.,Verify the effectiveness of fire protection measures.According to the conduction formula of heat transfer,a heat protection formula for fire protection applied to the isolated rubber lead bearing is derived,and the numerical calculation results are compared with the results of numerical simulation analysis to verify the correctness of the heat protection formula for fire protection.