摘要
精确测量拉索索力是进行斜拉桥健康监测和工作状态评估的关键。在不考虑垂度、刚度、边界条件等因素的影响的条件下应用振动频率显式公式法识别实际工程中的拉索索力,会造成相当程度的误差。首先,通过对考虑上述条件时的隐式拉索频率方程零根的数值求解,给出了索力和频率的间接计算方法;其次,通过数值仿真,研究了该方法对索振动频率和索力识别误差的规律;最后,在此基础上建立了进一步的经验误差修正公式。实例研究表明,与其他显式公式方法相比,基于频率方程数值解的方法显著提高了识别精度,在此基础上进行的经验误差修正,可进一步大幅提高索力索频的识别精度;与有限元模型修正法相比,建议的方法计算耗时更小。
Accurate cable tension identification is the key to health monitoring and condition assessment of cable stayed bridge.Error must not be overlooked when applying vibration based formulas to identify the tension of real cables under sag,stiffness and boundary conditions.By numerically resolving the implicit frequency function of real cables with the above conditions,the indirect cable force identification method and corresponding cable mode frequency calculation method are investigated.The error of tension is studied using numerical simulation,and an empirical error correction formula is presented to fit the relationship between cable force error and cable parametersξandλ2.A case study on two real cables form the Shanghai Changjiang bridge shows that the method discussed in this paper can increase the accuracy of the cable force and reduce computing CPU time compared with FEM.
出处
《振动.测试与诊断》
EI
CSCD
北大核心
2014年第2期247-253,395,共7页
Journal of Vibration,Measurement & Diagnosis
基金
国家自然科学基金资助项目(50978196)
国家重点实验室自主资助项目(SLDRCE09-D-01)
"十二五"国家科技支撑计划课题资助项目(2012BAJ11B01)
中央高校基本科研业务费专项资金和国家气象局气象行业科研专项经费资助项目(201306102)
关键词
拉索
索力
频率方程
数值法
cable
cable force
implicit frequency function
numerical resolution