基于概率密度演化理论的LRB隔震支座时变可靠度研究

铅芯橡胶隔震支座LRB （Lead Rubber Bearing）的等效水平刚度是隔震建筑物的重要力学指标，橡胶材料由于其复杂活跃的化学组分，在使用过程中极易发生老化，是LRB支座中随时间变化的活跃因素。考虑铅芯橡胶隔震支座中橡胶材料退化的时变性和随机性，引入时变变异系数。基于概率密度演化方法，得到LRB支座等效水平刚度的概率密度演化曲线和时变可靠度。结果表明，随着时间的增长，支座等效水平刚度产生增大的趋势，支座的可靠度发生非线性降低，老化对支座等效水平刚度的离散性产生了明显的影响。

Study on time-varying reliability of LRB isolated bearings based on probability density evolution method

The equivalent horizontal stiffness of a lead rubber bearing (hereinafter referred to as LRB) is an important performance index of isolated buildings.Due to their complex and active chemical composition,rubber materials are prone to aging during use which is an active factor that changes with time in an LRB support.This paper considers the time-varying nature and randomness of rubber material degradation in lead-core rubber isolation bearings,and introduces the time-varying coefficient of variation.Based on the probability density evolution method,the probability density evolution curve and time-varying reliability of the equivalent horizontal stiffness of LRB bearings are obtained.The results show that with the increase of time,the equivalent horizontal stiffness of the bearing tends to increase;the reliability of the bearing decreases nonlinearly;aging has a significant effect on the dispersion of the equivalent horizontal stiffness values of the bearings.