基于半波法的张弦梁结构索力测试的试验及理论研究

发布时间：2018-02-28 05:49

本文关键词： 张弦梁结构半波法索力测试有限元模型　出处：《辽宁工程技术大学》2015年硕士论文　论文类型：学位论文

【摘要】：张弦梁结构是近十几年发展起来的一种新型的结构形式,因其具有良好的受力性能,拉索高强度的抗拉性能,优美的造型及制作施工方便等优点在目前的建筑结构中得到了广泛的应用。拉索作为张弦梁结构的重要受力构件,其在役期间的受力状态关系到整个结构的安全及正常的运行,索力测试精度和实用性也直接影响着大跨度张弦梁结构健康监测的应用,因此能够准确的测出拉索在役期间的索力具有重要的现实意义。频率法是目前索力测试的主要方法,对于多撑杆的张弦梁结构而言,由于索段连接条件及环境因素会对测量的精度产生影响。针对多撑杆的张弦梁结构索段约束复杂和索力识别精度等问题,本文采用一种新的索力识别方法—半波法对索力进行识别,半波法是基于频率法的基础上而应用的一种方法,半波法的关键就是对高阶振型的识别,通过高阶进行索力的计算。首先,通过对张弦梁模型的试验研究,证明了半波法在张弦梁下弦拉索中进行索力测试的可行性。在两撑杆的张弦梁缩尺模型的中间跨布置传感器,通过人工激励局部索的振动来测量高阶振型半波长,利用简支单索模型识别整体张弦梁的拉索的索力,对高阶振型的测量可以得到更精确的拉索的索力。通过试验研究结果表明,利用半波法对张弦梁拉索进行索力测试是可行的,当测出4阶及以上振型时,可以得到更精确的索力。其次,根据黄河口模型试验厅现场实际结构建立有限元模型,通过施加应变的方式对拉索施加预应力,取其中一跨进行模态分析,通过高阶振型的半波长及相应频率计算索力。通过有限元分析可以看出,当取高阶振型时,其索力越接近拉索的真实的索力。并且半波法计算索力的原理简单,通过等效单索建立索力分析,也避免了复杂索的建模。
[Abstract]:The beam-string structure is a new type of structure developed in the past ten years. Because of its good mechanical properties and tensile properties of high tensile strength, The advantages of beautiful modeling and convenient construction have been widely used in the present building structure. As an important force member of the beam string structure, the stress state of the cable during service relates to the safety and normal operation of the whole structure. The accuracy and practicability of cable force test also directly affect the application of health monitoring of long-span beam string structure. Therefore, it is of great practical significance to accurately measure the cable force during the period of service. The frequency method is the main method of cable force testing at present. For the multi-braced beam string structure, the cable connection conditions and environmental factors will affect the accuracy of the measurement. In view of the complex constraints of the cable segment and the precision of cable force identification of the multi-braced beam structure, In this paper, a new method of cable force identification, the half wave method, is used to identify the cable force. The half wave method is based on the frequency method. The key of the half wave method is to recognize the high order modes. First of all, through the experimental research on the beam string model, it is proved that the semi-wave method is feasible to test the cable force in the string cable of Zhang Xian beam, and the sensor is arranged in the middle span of the scale model of the string beam with two strands. The vibration of local cables is artificially excited to measure the half-wavelength of high-order modes, and the simply supported single cable model is used to identify the cable force of the whole beam string. A more accurate cable force can be obtained from the measurement of high order modes. The experimental results show that it is feasible to test the cable force by using the half wave method, and when the fourth or more modes are measured, A more accurate cable force can be obtained. Secondly, according to the actual structure of the Huanghe Estuary Model Test Hall, the finite element model is established, and the prestressing force is applied to the cable by applying strain, and one of the spans is taken for modal analysis. Through finite element analysis, it can be seen that the cable force is closer to the real cable force when the higher-order mode is taken, and the principle of calculating cable force by half-wave method is simple. The cable force analysis is established by equivalent single cable, and the complex cable modeling is avoided.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU399

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