Damage Location of Beam Railway Bridges Using Rotation Responses under Moving Train Loads

Detection of potential damage is of great significance for aging railway bridges. In this paper, a damage location method for beam railway bridges based on the rotation response to operational train loading is presented. The method is based on deformation area analysis of the operational rotation response of bridges to the passage of trains. The theoretical basis of this method is elaborated. The calculated deformation curvature area difference ratio (CADR) change is used to identify damage in bridges. To obtain the curvature area, a technique is proposed for the curvature area calculation. The results are presented in terms of the damage condition extracted from each ratio, which was obtained by dividing the deformation area from the current interval to the sum of the areas from all the intervals. The location of damage was identified by observing the magnitude of the changes in the CADR. Finite element models were utilized to verify the method. The influences of train-track-bridge interaction and environmental temperature changes were considered. The calculation process is given for the application of the proposed method to the damage location of railway bridges. Thereafter, vehicle-bridge models with different parameters are investigated. The results show the capability of the method.