主梁转动惯量对框架式曲线桥自振特性的影响  

Effects of the Main Girder Inertia Moment on Natural Vibration Characteristics of the Frame Curved Bridge

作　　者：吴桐[1,3] 冯良勇 张双 Walter Yang 

机构地区：[1]佐治亚理工学院土木与环境工程学院,美国亚特兰大30332 [2]辽宁大通公路工程有限公司,辽宁沈阳110111 [3]辽宁省交通规划设计院,辽宁沈阳110166

出　　处：《沈阳建筑大学学报（自然科学版）》2015年第4期644-652,共9页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(50908005,51178008);美国加利福尼亚交通局资助项目

摘　　要：目的研究框架式曲线桥的自振规律,振型特点,分析主梁的转动惯量对曲线桥自振特性的影响,规范曲线桥动力模型中的质量布置形式.方法利用Open Sees平台建立框架式曲线桥的弹塑性纤维模型,比较不同主梁质量布置下曲线桥的特征值分析结果,获得主梁转动惯量对曲线桥自振特性的影响.结果框架式曲线桥在振动过程中,将产生向曲线外侧偏转的趋势;主梁在各框架的连接点处产生振动不一致现象,这易导致地震发生时铰接构造内的弹簧限位装置产生非线性行为.主梁转动惯量对曲线桥的自振特性影响较大;只考虑主梁三向平动质量而忽略全部转动惯量的动力模型所计算的曲线桥振型是不准确的.结论在三向平动质量的基础上只需要添加主梁绕纵轴的转动惯量,就可以减小特征值分析的误差,使动力计算结果达到满意的精度.Rules of natural vibration and vibration shapes of the frame curved bridge and effects of the main girder inertia moment on its natural vibration characteristics were studied in this paper. Using OpenSees platform, an elastic-plastic fiber model for the bridge was built. Through compa- ring of eigenvalue analysis results of the bridge by different mass arrangements, effects of the gird- er inertia moment on natural vibration characteristics of the curved bridge were obtained. Results indicate that there is an outward deflection trend during vibration of the frame curved bridge. It is found that vibration phenomenons at frame connection points are different, which may lead to non- linear behaviors in restrained devices in hinges by earthquake. Effects of the main girder inertiamoment on natural vibration characteristics of the bridge are obvious. It is inaccurate for calculating vibration shapes of the bridge, if only the three translational mass of the girder is taken into account without considering its inertia moment. Conclusion is that for a good accuracy of dynamic calcula- tion and reducing errors of eigenvalue analysis, the longitudinal inertia moment of the main girder need to be considered.

关 键 词：转动惯量 特征值分析 质量布置 框架式 曲线桥 

分 类 号：TU311.3[建筑科学—结构工程]