三等跨曲线连续梁模态分析试验  

Modal Analysis and Test on a Three-equal-span Continuous Curve Beam

作　　者：刘辉[1] 袁向荣[1] 覃继平 陈泽贤[1] 

机构地区：[1]广州大学土木工程学院,广东广州510006

出　　处：《实验室研究与探索》2016年第10期12-15,共4页Research and Exploration In Laboratory

基　　金：国家自然科学基金项目(51078093;51278137);广州市科技计划项目(12C42011564)

摘　　要：为了得到三等跨曲线连续梁(曲梁)的固有频率和振型,利用Midas有限元分析软件计算了曲梁的固有频率和振型,并对其进行了振动试验。试验结果采用DASP模态分析软件处理,得到曲梁的前3阶频率及振型,将试验结果与计算结果进行对比,证实振型变化的真实性,并对其冲击系数的取值进行了探讨。结果表明:曲梁前3阶频率的相对误差均不超过4%,振型基本吻合;曲梁的有限元计算频率均小于试验实测频率,且曲梁的前3阶频率均小于等跨直梁,刚度是影响同等跨径直梁和曲梁自振频率不同的主要因素。Since the ramp bridge can be widely used in the city overpass,it encourages people to strengthen the curved bridge research. In order to obtain the natural frequency and vibration mode of 3 equal span continuous curved beam,finite element analysis software Midas was used,and these dynamic parameters of 3 equal spans continuous beam model were measured,the DASP equipment were used for modal analysis to obtain the first three frequencies and vibration modes of 3 equal spans continuous curve beam. Two results were compared,and confirmed the authenticity of the vibration mode change,and curve beam impact factor was discussed. It was shown that,the relative error of the first three frequency is less than 4 %, and the vibration mode is basically identical. The curved beam finite element calculation frequency are less than test measured frequency,and the first three frequencies of curved beam are less than straight beam. Stiffness is the main factor affecting the same span straight and curved beams with different natural frequencies. In the current specification,the impact factor for straight beam is only defined and no clear rules are defined for curved beam,so it needs further research.

关 键 词：曲线连续梁 振型 模态分析 有限元分析 冲击系数 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]