索力振动法测量的试验研究

发布时间：2018-01-17 18:04

本文关键词：索力振动法测量的试验研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：索力是索体系桥梁在施工阶段进行施工监控的重要指标,也是桥梁运营阶段进行健康评估的重要指标。目前的索力测试方法中使用比较普遍的是振动法。利用振动法对索力进行计算的公式中,张紧弦公式忽略了索的刚度的影响,因而只对长索能保持较高的精度。铰接梁公式考虑了抗弯刚度的影响,且能够显式地推导出来解析解。两端固结边界条件下的索,一些学者通过引入有效计算长度,来使其可以简化为铰接梁。另一些学者通过拟合近似公式来求解。通过对两种思路的文献进行归纳总结,本文认为,拉索的索力和频率平方之间存在着线性关系。但是这种观点未能通过数学推导得到证明,因此本文试图利用试验的手段,通过数据对其进行检验。具体工作包括以下几点:(1)大量查阅利用振动法对索力进行测量的有关文献,对以前学者的研究工作进行整理分析,提出拉索索力和频率平方之间的线性关系,并提出基于等代铰接梁模型的频阶识别方法。并对文献中影响振动法索力测量精度的因素进行分析,在此基础上设计试验方案,从而减小这些因素的影响。(2)建立了不同长度和不同边界条件下拉索的有限元模型,得到不同索力下的各阶频率数据。利用铰接梁公式对两端固结和一铰一固边界条件下的频率数据进行计算。发现对于长、中、短索,利用线性模型进行索力计算均能保持很高的精度。并将计算结果和文献中常用的索力计算公式进行精度对比。(3)在恒温实验室下对大量拉索进行张拉试验,并利用试验数据对本文理论进行验证。通过对试验索的统计分析,发现在恒温实验室条件下,可以利用线性模型得出较高的精度。(4)利用南盘江桥索力试验时的三个较短吊杆的数据对吊杆力进行计算,验证在实际工程中线性模型的精度,并给出了本文方法在实际工程中的使用流程。
[Abstract]:Cable force is an important index to monitor the construction of cable-system bridges in the construction stage. It is also an important index of health assessment in bridge operation stage. The vibration method is widely used in the current cable force test method, and the formula for calculating cable force by vibration method. The tensioning string formula neglects the influence of the cable stiffness, so it only keeps a higher precision for the long cable energy, and the flexural stiffness is considered in the hinge beam formula. And the analytical solution can be derived explicitly. Some scholars calculate the length of the cable under the boundary condition by introducing the effective method. In order to simplify it to hinged beam, some other scholars by fitting approximate formula to solve. Through the two ideas of literature summarized, this paper thinks. There is a linear relationship between the cable force and the square of frequency, but this view can not be proved by mathematical derivation, so this paper tries to use the means of experiment. The specific work includes the following points: 1) to consult a large number of vibration method to measure the cable force of the relevant literature, to sort out and analyze the previous research work of scholars. The linear relationship between cable force and frequency square is presented, and the frequency order identification method based on the equivalent hinge beam model is proposed. The factors influencing the precision of vibration Burkina Faso force measurement are analyzed. On this basis, the experimental scheme is designed to reduce the influence of these factors. (2) the finite element model of the cables with different lengths and boundary conditions is established. The frequency data of each order under different cable forces are obtained. The frequency data under the condition of two ends consolidation and one hinge and one fixed boundary are calculated by using the formula of hinged beam. It is found that for long, medium and short cables. The accuracy of cable force calculation using linear model is very high, and the accuracy of the calculation results is compared with the commonly used cable force calculation formula in literature. 3) A large number of cable tension tests are carried out in the constant temperature laboratory. The experimental data are used to verify the theory of this paper. Through the statistical analysis of the test cable, it is found that under the condition of constant temperature laboratory. We can use the linear model to get a higher precision.) using the data of three shorter suspenders in the test of cable force of Nanpanjiang Bridge, we can calculate the force of the suspender, and verify the accuracy of the linear model in the actual engineering. The application flow of this method in practical engineering is also given.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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