Measurement And Numerical Simulation Analysis Of Road Traffic Induced Microvibration In Precision Instrument Laboratory

The study of structural vibration has always been a hot topic,and most previous studies have been limited to large-scale and large-scale vibration hazards caused by earthquakes or explosion shocks.With the development of various precision tools and instruments used in the microelectronics,medical and biopharmaceutical industries,anti-micro-vibration research in buildings has become a new development direction.The vibration limit of the general specification for the calibration of the building can no longer meet the requirements of the allowable vibration of such precision equipment.Therefore,this paper evaluates the ground micro-vibration of an ion center in Guangdong according to the internationally accepted ISOVC vibration guidelines.Taking road traffic as the main vibration excitation,through the monitoring of the actual site vibration signal,a multi-frequency sine wave vehicle load model based on road surface unevenness and a modified Kanai-Tajimi power spectral density function model were established.Based on MASW and EBL algorithms,the soil parameters of the actual site are inverted to establish a three-dimensional finite element model.The micro-vibration of the model is analyzed by two different load forms,and the vibration isolation effect of the vibration isolation barrier in this project is explored by combining different working conditions.This paper achieves the following results through research:(1)The vibration of the actual site is monitored,and the vibration velocity of each monitoring point decreases with the increase of distance,indicating that the vibration wave propagation in the soil will be attenuated.Moreover,through spectrum analysis,it is found that road traffic vibration mainly occurs at low frequencies,and the dominant frequency is between2-10 Hz.In addition,the load numerical model established based on the measured data is close to the measured response,indicating that the numerical model has a better effect.(2)The comparison between the soil dispersion curve of the measured data by the MASW method and the theoretical dispersion curve obtained by the inversion of the EBL algorithm shows that the consistency is good,and the algorithm begins to converge after about 250 iterations,indicating that the accuracy of the algorithm is high and the optimization ability is strong.(3)ANSYS was used to perform transient analysis and random vibration analysis of finite elements,and compared the two load models,and it was found that the target building model exceeded the limit of the vibration criterion of VC-A.By comparing the attenuation coefficients of the vibration isolation barrier under different working conditions,the continuous vibration isolation arrangement with a width of 3 meters and a depth of 8 meters under rubber materials was selected as the vibration damping measure of the model,and the vibration reduction model met the vibration criteria of VC-A.(4)Through MATLAB programming,an operating system for traffic micro-vibration was developed,and the functions of data processing,establishing traffic load and calling ANSYS calculation and post-processing output data were realized,which provided certain technical support for traffic micro-vibration analysis.