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对环境振动响应下悬索桥系统识别的应用进行研究和评估。为获得桥的动力特征,采用只有两个输出时间域的系统识别方法,即与Ibrahim时域方法相结合的随机衰减法,与特征系统实现算法相结合的自然励磁技术。研究两种方法的精度和效果并与有限元方法结果进行了比较。两种方法论证的系统识别的结果表明,环境振动测量可以提供桥动态特征的可靠信息。然而,与特征系统实现算法相结合的自然励磁技术更实用和有效,尤其是应用于多波段测量庞大数据时。3天的测量结果显示,风速与自然频率和阻尼比率相关,尤其在低阶模态时。这些相关信息明显受梁周围空气动力以及靠近索塔处摩擦力的影响
The application of suspension bridge system identification under environmental vibration response is studied and evaluated. In order to obtain the dynamic characteristics of the bridge, a system identification method with only two output time domains, a random attenuation method combined with the Ibrahim time-domain method and a natural excitation technique combined with a feature system implementation algorithm, is used. The accuracy and effect of the two methods are studied and compared with the results of the finite element method. The results of the system identification of the two methodological demonstrations show that environmental vibration measurements provide reliable information on the dynamic characteristics of the bridge. However, the natural excitation technique combined with the feature system implementation algorithm is more practical and effective, especially when applied to multi-band measurement of huge data. The 3-day measurements show that the wind speed is related to the natural frequency and damping ratio, especially in the low-order mode. This information is clearly influenced by the aerodynamic forces around the beam and the friction near the pylon