节点文献
旋转质量摩擦阻尼器限位摩擦摆隔震桥梁地震响应分析
Analysis on seismic response of frictional pendulum isolated bridges limited by Rotational Mass Friction Damper
【摘要】 针对现有隔震桥梁限位装置以及摩擦阻尼器存在的不足,利用机械领域常用的滚珠丝杠提出一种具有响应放大和负刚度效应的新型旋转质量摩擦阻尼器(Rotational Mass Friction Damper, RMFD)限位装置,介绍该装置的构造及作用机理,推导装置的恢复力计算公式,进行拟静力试验,设计装置在隔震桥梁中的布置方式,给出了在SAP2000中实现RMFD装置恢复力模型的方法,利用MATLAB和SAP2000对同一单自由度结构的响应进行对比,验证了方法的有效性。进而以某一6跨连续摩擦摆隔震桥梁为研究对象,利用SAP2000软件对比分析大震下非隔震桥梁、摩擦摆隔震桥梁以及RMFD限位摩擦摆隔震桥梁的地震响应、减震率、支座位移控制效果,以及等效摩擦力变化时墩柱响应峰值、减震率及墩柱损伤状态的变化情况。结果表明:RMFD作为桥梁隔震限位装置,仅需要较小的螺栓预紧力即可获得较大的RMFD阻尼器出力,位移行程大、耗能能力强,能够有效地将隔震层的位移控制在允许范围之内,避免支座位移超限引起的落梁、碰撞等震害的发生;同时,桥墩的墩底剪力、墩顶位移等地震反应稍有增大,减震率有所降低,但降幅均在10%以内,隔震桥梁仍具有良好的减震效果;随着等效摩擦力的增大,墩顶位移、墩底剪力、墩底弯矩最大值均不断增大,但支座的位移逐渐减小,说明螺栓预紧力越大,隔震层的位移控制效果越好,但其余地震响应的控制效果变差,桥墩损坏程度会加大,因此应合理设计预紧力的大小以取得理想的减震效果。
【Abstract】 Aiming at the shortcomings of the existing displacement restrainer and friction damper for isolated bridge, a new type of Rotational Mass Friction Damper(RMFD) displacement restrainer with response amplification effect and negative stiffness effect was proposed by using the ball screw commonly used in mechanical field, and the structure and mechanism of the device were introduced.The calculation formula for the restoring force of RMFD was derived, quasi-static tests were carried out, and the arrangement of RMFD in isolated bridges was designed.The method of realizing the resilience force model of RMFD device in SAP2000 was proposed, and MATLAB and SAP2000 were used for the comparison of the responses of the same single-degree-of-freedom structure, so that the effectiveness of the proposed method was verified.Furthermore, with a 6-span continuous friction pendulum isolated bridge taken as the research object, the seismic responses, isolation effect and displacement control effect of non-isolated bridge, friction pendulum isolated bridge and friction pendulum isolated bridge limited by RMFD were compared and analyzed.When the equivalentfriction force changes, the changes of response peak value, isolation rate and damage state of pier were also studied.The analysis results show that by applying small bolt pre-tightening force, RMFD, as the displacement restrainer of the isolated layer for friction pendulum isolated bridge, may achieve large damping force, large displacement stroke and high energy dissipation capacity of RMFD, may effectively reduce the displacement of isolated layer, and may avoid the occurrence of earthquake damages such as beam falling and collision caused by the displacement overrun of the bearing.At the same time, seismic responses such as pier bottom shear force and pier top displacement slightly increase, but the isolation effect decrease.Because the decrease range is within 10%, the isolated bridge still has good isolation effect.With the increase of equivalent friction force, the maximum values of pier top displacement, pier bottom shear force and pier bottom bending moment increase continuously, but the displacement of isolated bearing decreases gradually, indicating that the larger the pre-tightening force of bolt is, the better the displacement control effect of isolation layer shall be, although the control effect of other seismic responses becomes worse and the damage degree of the bridge pier may increase.Therefore, the pre-tightening force of bolt should be designed reasonably to obtain the ideal control effect.
【Key words】 Rotational Mass Friction Damper; frictional pendulum isolated bridges; seismic response; displacement restrainer; response amplification;
- 【文献出处】 土木工程学报 ,China Civil Engineering Journal , 编辑部邮箱 ,2023年02期
- 【分类号】U442.55
- 【下载频次】89