Pedestrian Bridge Dynamic Modeling And Vibration Control

Through the dynamic characteristic test of the built pedestrian bridge,it is found that a large number of pedestrian bridges were under excessive vibration problems. The first-order mode is the main vibration mode of pedestrian bridge. The first-order vibration frequency close to the normal pedestrian's frequency, so resonance can occur easily, cause excessive vibration and impact the structural safety, lead to psychological discomfort of pedestrians. In order to solve the problem, study on pedestrian bridge dynamic modeling and vibration control has been done.First, this article outlined the state of the art of the human-induced vibrations of footbridge, introduced single step walking force model, identification methods, calculation model and vibration control theory. Then using the designed beam, the thesis compiled statistics of the dynamic strain data of midspan under three different weight of pedestrian. Analyzing data, through the key points interpolation fitting of single foot step curve, this paper put forward three patterns of human load model for different speed (fast walk, normal walk, slow walk). According to the identified single footstep human load model, successive walking load model is constructed.The finite element method and modal superposition were used in calculating and comparing the dynamic response of midspan under singe footstep, successive footstep with the measured values of beam. Then taking a footbridge as an example, this paper compared the response of pedestrian bridge using two methods, took into account the parameters of the pedestrian bridge's response. TMD is used to control excessive vibration of the footbridge and the response of the pedestrian bridge under control is calculated. Finally, the comfort evaluation standards of pedestrian bridge vibration were introduced and used in evaluating vibration of uncontrolled and controlled pedestrian bridge.