4等跨连续梁模态试验分析及冲击因数研究  

Modal test and analysis on a four equal spans continuous beam and study of impact factor

作　　者：胡帮义 袁向荣[1] 杨勇[1] 陈泽贤[1] 刘辉[1] 

机构地区：[1]广州大学土木工程学院,广东广州510006

出　　处：《实验技术与管理》2015年第8期70-74,共5页Experimental Technology and Management

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：为了研究连续梁桥冲击因数与其固有频率和振型的关系,分析计算了4等跨连续梁的固有频率和振型,并进行了4等跨连续梁振动试验;通过分析和试验,确定梁的前四阶振型最大曲率位置,结合规范讨论了计算冲击因数时结构固有频率的选取。结果表明:当计算4等跨连续梁桥的正弯矩效应时,冲击因数计算采用基频是合理的;当计算负弯矩效应时,不应采用基频,应采用第2阶频率。In order to study the relation between the impact factor of continuous beam and the natural frequencies and mode shapes ,the natural frequencies and mode shapes of four equal spans continuous beam are calculated ,and these dynamic parameters of 4 equal spans continuous beam modal are measured .From the analysis and modal test ,the locations of the maximum curvatures of the mode shapes are determined .The selection of the natural frequency of the beam is discussed with the design code .It is shown that ,for the impact factor ,when the effect of positive bending moment is calculated ,it is reasonable to use the fundamental frequency ,and the 2nd frequency must be used when the effect of negative bending moment is calculated .

关 键 词：4等跨连续梁 冲击因数 模态试验 有限元分析 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]