加载频率与幅值对橡胶隔震支座力学性能的影响试验研究  

Study on loading frequency and amplitude effects to the mechanic properties of seismic isolation rubber bearings

作　　者：李勇 庞辉 戴君武[1,2] 孙得璋 姜涛[1,2] LI Yong;PANG Hui;DAI Junwu;SUN Dezhang;JIANG Tao(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Disaster Mitigation,Ministry of Emergency Management,Harbin 150080,China)

机构地区：[1]中国地震局工程力学研究所地震工程与工程振动重点实验室,黑龙江哈尔滨150080 [2]地震灾害防治应急管理部重点实验室,黑龙江哈尔滨150080

出　　处：《地震工程与工程振动》2023年第3期136-149,共14页Earthquake Engineering and Engineering Dynamics

基　　金：中国地震局工程力学研究所基本科研业务费专项(2019A03,2022C04);国家自然科学基金项目(52208509);黑龙江省自然科学基金项目(LH2022E121)。

摘　　要：为了探究加载频率、幅值对橡胶隔震支座水平等效刚度、特征强度、屈服后刚度、等效阻尼比及耗能等力学性能的影响,在实验室常温(25℃左右)环境中对直径为700 mm的典型常用天然橡胶支座和铅芯橡胶支座(共4个)进行了一系列的压剪试验,其中,加载频率变化范围为0.3~0.67 Hz,加载幅值变化范围为25%~250%。考虑到试验中加载设备摩擦力与惯性力的影响,本文对实测水平力进行修正并绘制出隔震支座的真实滞回曲线。实验结果表明:支座内部温度随加载频率的增大,升温越为明显,其中在最大加载频率下,天然与铅芯支座在前三圈循环下的升温幅度分别为5.24%和29.98%;随着加载幅值从25%~250%不断增大,隔震支座水平等效刚度和屈服后刚度的最大下降幅度分别为67%和55%,特征强度的增长幅度范围为64%~188%,且天然与铅芯支座耗能约增加15~26倍;此外,铅芯支座的内部温度上升幅度和各项力学性能均明显高于天然支座,但随着加载进行,铅芯支座的特征强度出现了更为明显的刚度退化,且在前三圈循环加载中天然与铅芯支座的特征强度分别退化了3.34%和12.2%。In order to explore the effects of loading frequency and amplitude on the mechanical properties of seismic isolation rubber bearings,such as equivalent horizontal stiffness,characteristic strength,post-yielding stiffness,equivalent linear damping ratio and energy dissipation,a series of compression and shear tests are carried out on typical common linear natural rubber bearing and lead-core rubber bearing(4 in total)with a diameter of 700 mm at room temperature(about 25℃).The variation range of loading frequency is 0.3~0.67 Hz,and the variation range of loading amplitude is 25%~250%.Considering the influence of friction and inertia force of loading equipment in the test,the measured horizontal force is corrected and the real hysteresis loop of seismic isolation bearing is drawn in this paper.The experimental results show that the temperature rise in the bearing is more obvious with the increase of loading frequency.Under the maximum loading frequency,the temperature rise ranges of linear natural rubber bearing and lead-core rubber bearing under the first three cycles are 5.24%and 29.98%respectively.With the increase of loading amplitude from 25%to 250%,the maximum decrease of equivalent horizontal stiffness and post-yielding stiffness of seismic isolation bearing are 67%and 55%respectively,the increase range of characteristic strength is 64%to 188%,and the energy dissipation of linear natural rubber bearing and lead-core rubber bearing increases by 15 to 26 times.In addition,the internal temperature rise and various mechanical properties of the lead bearing are significantly higher than those of the natural bearing,but with the loading,the characteristic strength of the lead-core rubber bearing shows more obvious stiffness degradation,and the characteristic strength of the linear natural rubber bearing and lead-core rubber bearing degrades by 3.34%and 12.2%respectively in the first three cycles of cyclic loading.

关 键 词：加载频率 加载幅值 橡胶隔震支座 水平等效刚度 特征强度 屈服后刚度 

分 类 号：TU352.1[建筑科学—结构工程]