Research On Human-Induced Vibration And Vibration Control Of Long-Span Corridor

The large-span structure usually has the characteristics of small damping and low natural frequency.When used,it is easy to coincide with the frequency of people’s normal walking.Under the excitation of walking,a large vibration is generated,causing panic in the mind of the pedestrian,and the comfort can not be guaranteed,which affects the normal use of the structure.Therefore,this paper takes the 45-meter span steel truss corridor in the Xi’an station building renovation project as the research background,systematically studied the human-induced vibration comfort of the long-span corridor and the vibration reduction control measures.The dynamic response of the steel corridor under the pedestrian load is analyzed,and the comfort is evaluated.The tuned mass damper(TMD)is proposed to reduce the vertical vibration response of the structure to ensure the comfort of the structure.The main work has the following aspects:Taking Chinese standards,international ISO,British BS5400,American AISC-11,and German EN03 as examples,the relevant regulations on the comfort problems of national norms and standards are reviewed.The simulation methods of pedestrian loads and the evaluation indexes of comfort are compared.A comfort evaluation standard suitable for steel structure corridors was selected as a basis for subsequent analysis.The finite element model of the steel corridor is established,and the vibration modal characteristics are analyzed.The deterministic crowd load conditions and random crowd load conditions that may occur during the normal use phase are defined.The time history analysis method is applied to calculate the response of the structure under various working conditions,and use the selected comfort evaluation criteria for evaluation.The influence of the thickness of the slab,the damping ratio of the structure,the interaction between the human and the structure on the comfort of the corridor is analyzed.The tuned mass damper(TMD)was introduced as the vibration reduction device.The vibration reduction principle of single frequency TMD and multi-frequency MTMD was described and the parameters were analyzed.The optimization parameter calculation method was summarized and it is installed on the corridor model for dynamic time history analysis.Comparing the calculation results of the vibration-damping structure with the original structure results,the reduction effect can make the vibration response of the corridor meet the requirements of the comfort standard,prove the applicability of the TMD device.The advantages and disadvantages of the TMD and the MTMD are discussed.In order to obtain more ideal damping effect,the genetic algorithm is introduced,With the reduction rate function as the objective function,the main program of genetic algorithm was written by Matlab,using Abaqus finite element software to calculate,The optimization method of TMD control for corridor vibration is given,which optimizes the TMD stiffness,damping parameters and MTMD position parameters,improves the vibration damping effect,and proves the effectiveness of genetic algorithm for structural vibration reduction optimization.The results were compared and some conclusions were drawn that are useful for guiding the design.