铜陵长江大桥主跨的环境随机激励模态测试

随机激励法是桥梁检测研究的主要方法,检测获得的模态参数是判断判断桥梁运行状况的重要标志。本文采用自行开发的一套基于PC机的测试系统,对铜陵长江大桥主跨部分进行环境随机激励模态测试,记录了大桥主跨部分的动态过程。通过分析测试结果给出了铜陵长江大桥主跨部分垂直方向上的前五阶对称振型和第三阶反对称振动的振型以及相应的固有频率.为了验证测试结果,文中对大桥用二维有限元模型建模,用有限元软件ANSYS建立了该桥的二维有限元模型,并计算得到了桥的模态参数。结果表明,计算和测试结果吻合较好,从而验证了本文测试方法的可靠性。

Ambient Vibration Studies of the Main Span of Tongling Yangzi River Bridge

Ambient vibration study has been a primary method in testing and monitoring of bridge structures. Modal parameters obtained from ambient vibration testing can be an important criterion for safety evaluation of bridges. A PC based testing system for ambient vibration testing of the main span of the cable Tongling Yangzi River Bridge is developed and the main procedure of testing is described. The analysis of the recorded data is also presented. Finally, the 1st, 2nd, 3rd, 4th, 5th symmetric, and the 3rd anti-symmetric vertical modes as well as the corresponding frequencies of the bridge are achieved. To verify the results, a 2D finite-element model of the bridge is developed and its modal parameters are calculated by using the finite element software ANSYS. It is shown that the tested and computed results are in reasonable agreement. This demonstrates the reliability of the presented testing system.