CHIA-MING CHANGCheng, ChiChiCheng2025-07-302025-07-3020259783857482069https://www.scopus.com/record/display.uri?eid=2-s2.0-105008760843&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/730813When a vehicle travels on a bridge, the interaction generated between the vehicle and the bridge is the main source of dynamic response in the system. To understand the characteristics and behavior of the vehicle-bridge interaction system, this study derives the instantaneous frequency response function of the system. In this research, a single sprung mass or multiple sprung masses are used to simulate the moving train. The assumed mode method is applied to simulate the bridge response in the form of the first mode or the superposition of multiple modes. Subsequently, the instantaneous frequency response function of the vehicle-bridge interaction is obtained. In this research, a parametric study is carried out to investigate multiple variables. As a result, the analytically instantaneous frequency response function is validated to be consistent with numerical results and has the potential to be employed in the structural monitoring of bridges in the future.falseassumed-mode methodbridge monitoringinstantaneous frequency response functionsmultiple modesnatural frequenciessprung massesvehicle-bridge interactionconference paper2-s2.0-105008760843