Damage Identification and Quantification Method for Bridge Bearings Based on Local Mode Shape Characteristics

Bridge bearings are important components that connect the upper and lower structures of bridges, and their health status directly affects the safety of bridges. However, existing bridge bearing damage identification methods have problems such as low sensitivity of damage indicators and susceptibility to environmental noise. Therefore, this study proposes a method of identifying, locating, and quantifying bridge bearing damage based on local mode shape characteristics. The bearing damage is identified by the bridge frequency change rate, the damage is located using the first-order local mode shape correlation coefficient of the bridge, and the damage degree is quantified by the first-order local mode shape difference wavelet coefficient. The proposed method is verified using finite element (FE) simulation and laboratory tests. The results show that the voiding of the side bearing has a greater impact on the second-order frequency of the bridge, while the voiding of the middle bearing has a greater impact on the third-order frequency. The first-order local mode shape correlation coefficient and the first-order local mode shape difference wavelet coefficient can successfully locate and quantify the damage. This method realizes the rapid evaluation of the bridge bearing status and provides technical support for the identification, location and quantification of bearing damage.