K-HHT Method And Its Application In Bridge Monitoring Research

K-HHT method is one introduced Kriging method in the HHT method, improved end effectsand modal aliasing exsited in HHT method. Therefore further research would be done for K-HHT method in this paper, selection of Kriging model and false component identification method is discussed,and which is applied to the large cable-stayed bridge cable force signal, in order to improve the recognition accuracy. The main research contents include:(1)Analysis of different forms of Kriging model influencing on K-HHT method. At present a total of 21 kinds of Kriging model, respectively consists of different correlation model(include:spline function, the gaussian function, exponential function, cubic function,the spherical function, linear function, generalized index) and regression model(include:constant type, a type, quadratic). The whole paper presents the constant frequency and variable frequency analog signal as the decomposition object, the experienced modal function as the decomposition effect, Hilbert spectrum, the three dimensional joint time-frequency analysis, the correlation coefficient as evaluation indicators, comparison of signal processing effect of K-HHT method of based on the different Kriging model.The results show that the Kriging model with the composition of constant style and the spline function is the optimal model, and K-HHT method based on the optimal Kriging model is suitable for constant frequency and variable frequency analog signal processing.(2) Methods study for false component identification. Analysis signal after K-EMD decomposition tends to have false component. For this, from the perspective of probability,this article is introduced K-S inspection method for identifying the authenticity of false component, giving studies about the design of variable amplitude and phase angle, analysis of influence that frequrncy has on the K-S inspection methods, and it puts forward the theoretical cumulative distribution function, based on the analysis of the results, expand theuse of the K-S testing method,That is, from one dimensional signal component recognition to multidimensional signal component. Case study shows that for the multidimensional signal, in this paper, the improved method has obvious effect on identification of false component and lays the foundation of monitoring signal processing.(3) Methods research for cable force identification. Based on the cable force identification method is put forward, with the structure modal parameters and FFT to compare and analyse. In the case of long and short cable respectively, and to study the strength and weakness of the three methods in the treatment of the cable-stayed bridge cable force monitoring signal. The analysis results show that method proposed in this paper is suitable for this kind of signal, especially the long cable vibration signal processing and analysis.