Vertical Vibration Serviceability Simulation Analysis Optimization Of Long-span Prestressed Secondary-beam Floor In Gymnasium

The long-span prestressed secondary-beam floor in the 2 layer of construction project 3#(gymnasium)building of Core Area Primary School in Tongliang county in Chongqing was taken as the research subject,aimed at the problem of vertical vibration comfort of similar long-span floor,the finite element model of long-span prestressed secondary-beam floor structure was established accurately by the finite element software ANSYS,the vertical vibration modal of the long-span floor was analysed on simulation,then it was compared with the measured results to verify the applicability and accuracy of the refinement modeling ideas and methods.On this basis,the factors that may affect the accuracy of the simulation analysis results and the calculation time of long-span floor comfort were analyzed,the optimum values of parameter settings for simulation analysis were obtained by orthogonal experiment,and the measured results of the peak accelerations of the floor under the four types of typical human-induced loads,such as walking,in-situ jumping,running and in-situ stepping,were taken as the basis for the evaluation of the simulation results,verified the applicability and accuracy of the optimized parameters,and evaluated the effect of improving the calculation efficiency of the simulation of long-span floor comfort.The main conclusions are:(1)Under the condition of weak vibration,the fine degree of the model is higher,the relevant influencing factors should be considered more detailed,according to the above guiding ideology to established a finite element model,a series of research on the idea and method of fine modeling of the long-span floor structure by finite element analysis software ANSYS.The results show that the modal analysis results accord with the universal law of the vibration modes of this kind of structure.It is proved that the refinement modeling idea and method obtained in this paper are feasible.(2)Through the field measurement,the dynamic characteristics of the long-span floor and the vertical vibration acceleration of the structure under four types of typical human-induced loads,single or multiple excitations were obtained.The results show that the measured modal results are in good agreement with the modal simulation results,it is proved that the refinement modeling idea and method obtained in this paper are feasible once again.The measured results of vertical vibration acceleration can be used as a reference for further study.(3)For the four main factors,such as the size of the grid,the structural damping ratio,the number of induced load loads and the time step of the integration,complied with the principle of a single factor change,used the fine geometric model established in this paper,study the influence of the above factors on the accuracy and calculation time of the long-span floor model and the transient dynamic analysis results based on single in-situ jumping,and the transient dynamic analysis of the floor under the effect of single continuous walking was carried out by orthogonal test.The results show that the influence of above four factors on the accuracy of calculation results and the calculation time of the vertical vibration acceleration of single motion form in different touchdown motions are substantially the same.Finally,the comprehensive balance method was adopted to obtain the optimal values of the parameters for the simulation analysis.(4)The measured results of the peak accelerations of the floor under the four types of typical human-induced loads were taken as the basis for the evaluation of the simulation results,based on the simulation analysis parameters,the corresponding structure vibration response simulation analysis was carried out.The results show that the simulated results of the peak acceleration of the single-person and three-person synchronous load are in good agreement with the corresponding measured results,with the increase of the number of the above three types of human-induced loads,the relative error of the structural peak acceleration simulation results and the corresponding measured results gradually increased,the synchronization problem is the main source of the error in the simulation analysis.(5)The error of the simulated results under the action of single in-situ stepping was larger,it’s mathematical model and simulation method should be studied in depth.(6)Compared the calculation time of comfort simulation analysis before and after parameter setting optimization,the optimized parameter setting could improve the calculation efficiency by more than 1 times.