基于改进多重同步压缩算法的斜拉索时变索力识别  

Identification of time-varying cable force based on an improved multisynchrosqueezing transform

作　　者：刘迅 卓卫东[1,2] 杨宁 林楷奇[1,2] LIU Xun;ZUO Weidong;YNAG Ning;LIN Kaiqi(College of Civil Engineering,Fuzhou University,Fuzhou 350108,China;Fujian Provincial Key Laboratory on Multi-Disasters Prevention and Mitigation in Civil Engineering,Fuzhou 350108,China)

机构地区：[1]福州大学土木工程学院,福州350108 [2]福建省土木工程多灾害防治重点实验室,福州350108

出　　处：《振动与冲击》2023年第12期212-219,共8页Journal of Vibration and Shock

基　　金：福建省高校产学合作项目(2019Y4003);福建省土木工程多灾害防治重点实验室(MPPC-202100X)。

摘　　要：斜拉索时变索力的识别是斜拉桥结构状态评估和健康诊断的重要内容,然而目前此问题尚未得到很好的解决。基于改进多重同步压缩算法和高效脊线提取算法,提出一种斜拉索时变索力识别新方法。该方法利用拉索振动加速度响应获得时频谱,通过提取时频谱中的时频脊线得到拉索的瞬时振动频率,并根据张紧弦理论计算拉索时变索力。通过典型斜拉桥数值案例和拉索试验对该方法的适用性和精度进行验证。结果表明,在数值案例中,在10%噪声水平下时变索力识别平均误差在1.99%以内,最大误差为5.09%;在试验案例中,时变索力识别平均误差在2.52%以内,最大误差为8.77%。初步检验结果证明了所提方法具有较好的识别精度和噪声鲁棒性。Identification of time-varying cable force is an important content of structural condition evaluation and health diagnosis of a cable-stayed bridge.However,this problem has not been well solved so far.Based on an improved multisynchrosqueezing transform and an efficient ridge extraction algorithm,a new method for time-varying cable force identification of stay cables was proposed in this paper.Firstly,the time-frequency spectrum was obtained by using the vibration acceleration response of the cable,and then the time-frequency ridge in the time-frequency spectrum was extracted to obtain the instantaneous frequency of the cable.Finally,the time-varying cable force was calculated according to the tension string theory.The applicability and precision of the method were verified by a typical numerical case of cable-stayed bridge and cable tests.Results show that:in the numerical case,under the noise level of 10%,the average error of time-varying cable force identification is less than 1.99%,and the maximum error is 5.09%;in the test,the average error of time-varying cable force identification is less than 2.52%,and the maximum error is 8.77%.The preliminary verifying results prove that the proposed method has good identification accuracy and noise robustness.

关 键 词：结构健康监测 斜拉索 时频分析 时变索力 同步压缩算法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]