斜拉索索力估算中振动信号处理方法的改进

Data processing of vibration signals for cable tension estimation

随机振动法是检测斜拉索拉力的有效方法,采用经典谱估计的方法对数据进行处理,其精度会受到快速Fouri-er变换(FFT)栅栏效应的影响,为此采用离散时间序列Fourier变换(DTFT)方法实现对斜拉索固有频率的精确搜索,以提高随机振动法求解斜拉索拉力的精度。对塘沽海河斜拉桥拉索的振动数据进行处理以求解加载前后斜拉索的拉力,结果表明:DTFT方法比FFT法求解的精度提高了5%。

The random vibration method is often used to measure the tension forces in the cables, but the accuracy of the classical spectrum estimate used to process the data is limited by the fence effect of the fast Fourier transform (FFT). Therefore, the discrete time Fourier transform (DTFT) method was used to determine accurate values of the cable's natural frequencies and to promote the precision of the random vibration method. Experiments on the cablestayed bridge over the Haihe River in Tanggu show that the accuracy of the change in the tension force with loading can be improved by 5% by using DTFT to eliminate the FFT fence effect.