张弦结构索力测试方法与工程试验研究

Research on measurement method and engineering test of cable force of string structure

在索振动频率和索力计算理论研究的基础上,提出针对短粗索和多跨索的多阶频率索力测试方法。多阶频率法有两种算法,一种基于优化算法,一种基于有限元法。基于优化算法的多阶频率法,通过实测不少于未知参数个数的多阶频率,对建立的考虑弯曲刚度的振动频率超越方程进行优化求解,可以确定任意弹性边界条件拉索的索力。基于有限元法的多阶频率法,通过建立多跨索振动模型,利用计算表格代替优化算法操作选择最接近真实值的索力,可以对复杂索结构进行分析。通过黄河口模型试验厅和农业展览馆两个实际工程,分别对基于优化算法和基于有限元法的多阶频率法的适用性进行验证。结果表明,提出的多阶频率法可以将索力偏差控制在10%以内,满足工程应用的精度要求,可以为张弦结构索力测试和施工技术研究提供技术支撑和参考。

Multi-frequency cable force measurement method for short-thick and multi-span cables was proposed based on the theoretical research of cable vibration frequency and cable force calculation.Multi-frequency method has two algorithms,one is based on optimization algorithm,the other is based on finite element method.For multi-frequency method based on optimization algorithm,the established vibration frequency transcendence equation considering bending stiffness is optimized by measuring the multi-order frequencies with no less than the number of unknown parameters,and the cable force under arbitrary elastic boundary conditions can be determined.For multi-frequency method based on the finite element method,the calculation table is used instead of the optimization algorithm to select the cable force closest to the real value by establishing the multi-span cable vibration model,which can be used for the complex cable structure.The applicability of the multi-frequency method based on optimization algorithm and finite element method was verified by two practical projects:the Hall of the Yellow River Estuary and the Agricultural Exhibition Hall.The results show that the multi-frequency method proposed can control the cable force deviation within 10%,which can meet the precision requirements of engineering applications.It can provide technical support and reference for cable force testing and construction research of string structures.