【作者】 王蓓；

【导师】 王凯；

【作者基本信息】 西安理工大学 ， 机械电子工程， 2008， 硕士

【摘要】 斜拉桥具有较好的跨越能力,因而在近些年来得到了广泛的应用。斜拉桥及桥上的拉索易在风雨激励、地震以及车载等外部载荷作用下产生振动,严重时会发生桥梁事故,因此探寻合理有效的方法来减小斜拉桥和拉索振动已经成为重要的研究课题。本文首先根据有限单元法理论,利用ANSYS软件选用LINK10和BEAM4单元对斜拉桥的拉索、主梁和桥塔等构件进行模拟,建立斜拉桥整桥有限元模型并对其动力特性进行分析,得出斜拉桥固有频率及相应的振型。发现斜拉桥易于产生大幅振动,同时也发现斜拉桥的振动具有明显的三维性。本文对拉索的构造方法、振动形态进行了分析,并将单根拉索的动力特性与由四根和七根钢绞线构成的拉索分别进行比较,发现在斜拉桥的建模过程及拉索动力特性分析过程中,可以用单根拉索来模拟由多根钢绞线构成的拉索。将利用解析法计算出的拉索固有频率与选用LINK10单元模拟单根拉索分析得到的拉索固有频率进行比较,发现最大相对误差不超过10%,从而进一步说明可以用单根拉索来模拟多根钢绞线构成的拉索。通过比较在斜拉桥上广泛采用的多种拉索减振方法,设计出基于高阻尼橡胶的减振装置。针对不同型号的高阻尼橡胶圈,设计出四因素三水平的正交实验方案,完成橡胶圈的动力特性研究,选择合适的橡胶圈作为减振装置的重要构件。本文对安装减振装置前后拉索节点的振动位移进行了模拟和比较,发现拉索减振装置的减振效果明显。通过改变拉索减振装置的安装位置,可以看出在一定范围内,随着安装位置的提高,减振效果越来越好。本论文利用有限元软件,对斜拉桥、拉索、拉索减振装置进行了研究,在研究过程中将ANSYS计算结果与实桥测量结果或解析计算结果进行对比,证明了本论文研究结论的正确性。论文研究内容对于斜拉桥的动力特性分析和拉索减振装置的设计具有一定的参考价值。更多还原

【Abstract】 With greater ability to go span obstacle, cable-stayed bridge is widely used in recent years. Cable-stayed bridge and stay cables are prone to vibrate under wind, rain, earthquake and vehicle loads. Sometimes vibration can lead to bridge accident. So it is important to search effective and reasonable method to reduce cable-stayed bridge vibration.According to finite element method principle, this paper adopts LINK10 unit and BEAM4 unit to simulate stay cable, beam and bridge tower in ANSYS. Establish a cable-stayed bridge model and analysis its dynamic characteristic. From above, obtain inherent frequency and corresponding model of cable-stayed bridge. The result proves that cable-stayed bridge vibrates easily and it shows three dimensions vibration properties.This paper analyses stay cable’s construction and vibration forms. Compare the dynamic characteristic of single cylindrical pole stay cable with that of stay cables which are composed by four steel wires and seven steel wires. Compare the inherent frequency of stay cable obtained by analytic method and ANSYS software. The comparison result indicates that the most error is less than 10%. The result also indicates that we can use single cylindrical pole stay cable to simulate stay cable which is composed by a cluster of steel wires.By comparing several kinds of vibration reducing methods which are widely used on cable-stayed bridge, a vibration reducing equipment has been worked out. For different models of high damp rubber rings, four factors three level orthogonal experiment table is designed out to do much investigation on their dynamic characteristics. The paper simulates and compares vibration displacement of nodes on stay cable, the result indicates that the vibration reducing effect of vibration reducing equipment is obvious. Changing the installation positions of stay cable vibration reducing equipment, the result indicates that the higher installation position the better vibration reducing effect in certain scope.The paper uses finite element software to do research on the cable-stayed bridge, stay cable and vibration reducing equipment. Compare the result obtained by ANSYS calculation, practical measure and analytic calculation. The research result proves its correctness. The paper’s research content and results have value of reference for dynamic analysis of cable-stayed bridge and designing of stay cable vibration reducing equipments.更多还原