基于ERA算法的大桥斜拉索索力检测方法

Detection of bridge cable force based on ERA

斜拉桥拉索模态参数(固有频率、阻尼比)在索力测试、拉索减振、实时控制等方面起着重要作用。目前斜拉索索力一般以频域分析法(如频差法等)进行检测,提出采用ERA算法来获取拉索自由响应信号中的各阶模态参数,从而给出更加精确稳定的拉索基频和对应索力,并与传统索力测算方法——功率谱峰值法进行对比分析。本文方法简单,与理论值吻合良好,试验容易实施,具有较好的工程实用价值。数字仿真与工程测试结果表明了方法的有效性和可行性。

The mode parameters of cable-stayed bridges（e.g.inherent frequency,damping ratio） play an important role in the force test,the shock absorption of cable and real-time control.Presently,the traditional method used to detect cable forces is the method in frequency domain（such as frequency difference method）.The method of detecting the cable force using ERA to obtain the mode parameters in each order from free response signal,then obtain the more ac-curate and stable base frequency and corresponding cable force,is presented,and the comparison of the ERA method and traditional method is also given in the paper.The presented method in this paper is simple,easy implementation,suitable for practical applications,and the result is close to theoretical value.The digital simulation and engineering test results show that the method is effective and feasible.