基于压电阻抗和主成分分析的斜拉索覆冰监测

In this study, based on electro-mechanical impedance (EMI) and principal component analysis (PCA), the monitoring of icing on bridge stay cables was investigated considering that bridge stay cables are prone to ice falling under middle and high latitudes. The EMI-based damage detection methods are sensitive to the changes in local stiffness and mass in structures. Icing on the surface of stay cables affects the local dynamic properties of both the structure and the piezoelectric sensor attached on the structure surface. This work first presents the principle of EMI-based icing monitoring and the common damage indices, and then analyzes the influence of temperature. Moreover, a series of experiments on stay cable model were conducted to obtain the electrical impedance spectrum curves affected by both the ice and temperature. The relationship between peak conductance, peak frequency, conductance mean value, standard deviation and ice thickness are investigated. PCA was employed to eliminate the effects of temperature and identify the ice thickness. The analysis results show that the above methods can effectively identify ice and non-ice conditions and monitor the conditions with different ice thickness.It has great significance for deicing.