In order to provide a theoretical reference for implementing moving vehicle excitation modal tests,the dynamic response patterns and dynamic characteristics of bridges under vehicle loading are investigated.Numerical simulation methods are used to examine the vibration response and the modal parameter identification of bridges under the action of moving vehicles.A finite element model of vehicle-bridge coupling system is established using ANSYS and the vibration response of the bridge was calculated under different parameter conditions such as vehicle speed,road roughness,and vehicle weight.The analysis shows that the bridge's displacement response has a maximum value in the speed range of 10-30 km/h when the vehicle is traveling at a constant speed,and the acceleration response increases with the increase of vehicle speed.Both displacement and acceleration responses increase with the increasing of road roughness.The displacement response is greatly influenced by vehicle weight in the quasi-static component compared with the dynamic component.Modal parameters of the bridge are identified using analytical mode decomposition(AMD)combined with stochastic subspace identification(SSI)algorithm for the entire processed data and the algorithm based on eigenvalue decomposition for free vibration data.The identified results show that the obtained modal frequencies and damping ratios are more accurate when the vehicle speed is in the range of 10-30 km/h.Therefore,selecting appropriate vehicle speeds according to identified modal features is crucial when using moving vehicles for modal testing of bridges.
关键词
振动与波/车致振动/有限元分析/动力响应/自由振动/模态参数识别
Key words
vibration and wave/vehicle induced vibration/finite element analysis/dynamic response/free vibration/modal parameter identification
维普
万方数据