基于概率密度演化的铅芯橡胶支座水平等效刚度不确定性  

Uncertainty of equivalent horizontal stiffness of lead-rubber bearings based on probability density evolution method

作　　者：薛斌 朱玉华[1] 何毅 卢文胜[1] XUE Bin;ZHU Yuhua;HE Yi;LU Wensheng(School of Civil Engineering,Tonal University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《地震工程与工程振动》2018年第6期145-152,共8页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金重点项目(E0808);国家自然科学基金项目(51578411)~~

摘　　要：铅芯橡胶支座水平等效刚度是影响水平隔震效果的主要指标,其材料特性及尺寸参数等在制作过程中存在变异性,因而引起支座水平等效刚度的不确定性。本文考虑铅芯橡胶支座四个尺寸参数和四个材性参数的变异性,引入变异系数,基于概率密度演化方法得到支座水平等效刚度的概率密度曲线(PDF),引入保证率,分析参数变异对支座水平等效刚度不确定性的影响。结果表明:尺寸参数中的单层橡胶厚、支座直径、铅芯直径,材性参数中的橡胶剪切模量、铅芯屈服强度,对PDF曲线离散性影响较大,相应的刚度结果保证率较小,不确定性较大。除钢板层厚度外,尺寸参数变异时PDF曲线的离散性均大于材性参数变异时情况,其引起的水平等效刚度不确定性普遍较大。本文研究单参数独立变异对水平等效刚度不确定性的影响,为后续多参数综合变异时的相关研究进行前期探索。The equivalent horizontal stiffness is one of the main factors which influence the isolation performance of lead rubber bearings. Uncertainty of the equivalent horizontal stiffness usually exists due to the uncertainty of the material properties and geometry parameters during manufacture. Variation of four geometry parameters and four material property parameters are focused on in this research, and variation coefficient is introduced to consider their variability. Probability density function(PDF) of the equivalent horizontal stiffness is obtained with the probability density evolution method. Assurance rate is introduced to study the influence of the parameters variability on the uncertainty of the equivalent horizontal stiffness. Analysis results show that PDF discreteness of the thickness of single rubber layer, bearing diameter and lead core diameter in geometry parameters, the shear modulus of the rubber and the yield strength of the lead core in material property parameters is relatively larger. Assurance rate of stiffness is smaller. The uncertainty level of stiffness is higher. Except the steel plate thickness, PDF discreteness and uncertainty level of geometry parameters is larger than that of the material property parameters. In this paper, the influence of single parameter variation on the uncertainty of horizontal equivalent stiffness is studied. It is a preliminary study for the subsequent research work on the comprehensive variation of multiple parameters.

关 键 词：铅芯橡胶支座 水平等效刚度 概率密度演化法 变异系数 不确定性 

分 类 号：TU352.1[建筑科学—结构工程]