庄文娟，朱玉华
    (同济大学土木工程学院，上海200092)

[摘要] 通过建立铅芯橡胶隔震支座的ANSYS模型，主要研究了铅芯橡胶隔震支座(LRB)的等效阻尼比和耗能特性的影响因素。采用铅芯橡胶支座四分之一模型模拟支座在水平正弦波荷载作用下的滞回曲线，大大缩短了有限元软件运行的时间，提高效率并获得较好的结果。分析结果表明，LRB的阻尼特性主要与水平剪应变、铅芯直径有关。水平位移越大，等效阻尼比越小，能量耗散越大；铅芯直径越大，等效阻尼比和能量耗散同时都增大。分析还表明，竖向面压、橡胶剪切模量、第二形状系数对阻尼特性的影响很小。可见，在一定的地震烈度下，阻尼的选取主要与铅芯直径有关。
[关键词] 铅芯橡胶支座；双线性滞回模型；等效阻尼比；耗能；铅芯直径；ANSYS模型

    Finite element analysis on damping properties oflead-rubber bearings
    Zhuang Wenjuan,  Zhu Yuhua
    ( College of Civil Engineering, Tongji University, Shanghai 200092, China)

Abstract: The equivalent linear damping ratio and the energy dissipation oflead-rubber bearings are studied by finite element simulations of lead-rubber bearings. The FEA program ANSYS is adopted to establish a quarter model of lead-rubber bearing to simulate the hysteretic curve of LRB under the sinusoidal load, which not only reduce the operating time, but also improve the efficiency and show a good agreement with the actual situation. It is demonstrated that the horizontal shear strain and diameter of the lead have a primary influence on damping properties. The results are that the equivalent linear damping ratio decreases, the energy dissipation increases as a result of the horizontal shear stain increasing. And the both properties increase with the diameter of lead increasing. In addition, the damping is almost no affected by compression, shape factor and shear modulus of rubber. Finally, in a certain seismic intensity, it can be seen that the selection of damping mainly relates to the diameter oflead.
Keywords: lead-rubber bearings; equivalent linear damping ratio; bilinear hysteretic model; energy dissipation; the diameter oflead; ANSYS model