金属橡胶桥梁支座疲劳试验研究  

Fatigue test of metal rubber bridge bearings

作　　者：张恒 夏修身[1] 乔鑫 朱志杰 戴胜勇[2] ZHANG Heng;XIA Xiushen;QIAO Xin;ZHU Zhijie;DAI Shengyong(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《振动与冲击》2024年第6期273-279,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(52278186;52068041);兰州交通大学天佑创新团队(TY202007)。

摘　　要：以某公路桥梁为工程背景,设计并制作了两个足尺金属橡胶桥梁支座试件,开展了200万次的竖向疲劳试验,探讨了疲劳前后支座力学性能的变化规律。在疲劳试验过程中每隔20万次进行了一次压缩试验,得到了一组支座竖向压缩滞回曲线。疲劳试验前后分别进行了支座压剪试验,得到了支座水平剪切滞回曲线。引入疲劳损伤因子对金属橡胶桥梁支座的疲劳损伤进行了定量表征。结果表明:金属橡胶桥梁支座疲劳损伤主要表现为内部金属丝之间的磨损、局部断丝、掉丝。疲劳损伤会显著降低支座一侧的水平承载力、屈服后刚度和等效剪切刚度,且使支座的水平剪切滞回曲线变得明显不对称,但会增大支座的整体耗能能力。支座竖向等效刚度及等效阻尼比随着疲劳加载次数先增大后减小然后再趋于稳定。200万次疲劳循环后的剪切等效刚度、竖向等效刚度及竖向等效阻尼比损伤因子均小于0.3,支座具有良好的疲劳性能。Taking a highway bridge as the engineering background,two full-scale metal-rubber bridge bearing specimens were designed and fabricated,and vertical fatigue tests of 2 million times were carried out to explore the change of mechanical properties of the bearings before and after fatigue.During the fatigue test,compression tests were conducted every 200000 cycles,and a set of vertical compression hysteresis curves of the bearings were obtained.The horizontal shear hysteresis curves were obtained from the bearing compression shear tests before and after the fatigue test.The fatigue damage factor was introduced to quantitatively characterize the fatigue damage of the metal-rubber bridge bearings.The results show that the fatigue damage of the metal-rubber bridge bearing was mainly manifested by the wear between the internal metal wires,local wires break and wires loss.The fatigue damage will significantly reduce the horizontal bearing capacity,post-yield stiffness and equivalent shear stiffness at one side of the bearing,and make the horizontal shear hysteresis curve of the bearing become obviously asymmetric,but will increase the overall energy dissipation capacity of the bearing.The equivalent shear stiffness,equivalent vertical stiffness and equivalent vertical damping ratio after 2 million fatigue cycles are less than 0.3,and the bearings have good fatigue performance.

关 键 词：桥梁工程 金属橡胶 支座 疲劳试验 损伤因子 

分 类 号：U443.361[建筑科学—桥梁与隧道工程]