This study investigates the effects of diaphragms on vehicle–curved bridge coupled vibrations by establishing a finite element model of a three‐span continuous girder curved bridge with a single‐box double‐cell cross section and a curvature radius of 250 m, and a vehicle moving system model in COMSOL. The effects of diaphragms on the mode shapes and natural frequencies of the bridge were analyzed based on an iterative algorithm compiled in COMSOL and MATLAB. The dynamic responses of the curved bridge with or without diaphragms were compared under the condition of Grade C surface unevenness. The results indicated that diaphragms significantly affected the torsional vibration modes of the curved bridge and substantially suppressed its torsional vibrations. Under static loads and low vehicle speeds, the diaphragms reduced the vertical and lateral displacements at the mid‐span of the curved bridge. At high vehicle speeds, however, the diaphragms intensified the vehicle–bridge coupled vibrations in those two directions, thereby increasing dynamic stress while undermining bridge safety and driving comfort. These findings provide a preliminary theoretical basis for improving the structural design of newly constructed curved bridges and optimizing the maintenance and reinforcement of existing bridges.
Chen et al. (Thu,) studied this question.