Study On Coupled Vibration Response And Vibration Isolation Countermeasures Of Structures Under Vehicle Loading

Along with the further development of city space,city roads and large complex buildings composite system increasingly appear,the speeding cars on municipal roads bring problems such as vibration and noise overrun,at the same time,car low-frequency vibration has influence on the comfort of human body,therefore,it is necessary to adopt vibration reduction and isolation measures for joint building system.This paper takes the joint construction of Wanhui No.1 Road and underground space in the core area of Wanbo Business Center,Panyu District,Guangzhou City as the engineering background.Through numerical simulation and field vibration tests,the coupling vibration of the structure under vehicle load,the vibration isolation performance of the floating slab road and the vibration comfort of the road under vehicle load are studied in depth.The research results can provide reference for the further application of steel spring floating slab road and the study of vehicle-induced vibration of municipal road buildings.The main work is as follows:1.The dynamics equations of the vehicle system and the floating plate system were established based on the force balance and displacement at the wheel.The Newmark-βmethod is used to separate and iteratively solve the vibration response of the system.The numerical simulation of road roughness was carried out by AR autoregressive model with the help of MATLAB,and the time domain data of class A ～ C roughness under the change of vehicle speed are obtained.Through the program,the coupled vibration algorithm of vehicle structure is verified,and the maximum mid-span deflection and impact coefficient of displacement are similar to the results in literature.The coupled vibration algorithm of vehicle structure has good accuracy and reliability.2.To set up the floating slab underground space structure coupled finite element model of ANSYS,firstly,modal analysis of floating slab vibration isolation road is carried out.Then,the amplitude frequency characteristics of the foundation reaction and the amplitude frequency characteristics of the force transmissibility are obtained by analyzing the harmonic response of the floating plate vibration isolation road.The parametric effects of spring stiffness and damping of vibration isolator are studied at the same time.Finally,a transient dynamic analysis model was established based on the displacement contact method.Considering the influence of parameters such as vibration isolation,road roughness and speed,the vibration observation points at the floating plate,roof and negative floor were set to extract and analyze the acceleration,displacement and other dynamic responses.3.The field vibration test of steel spring floating plate vibration isolation road is carried out,and the driving vibration test of sports car is carried out before and after the installation of floating plate,four kinds of common vehicles on municipal roads are used to excite the system by changing the speed and axle load.The acceleration measuring points of floating slab,roof,the negative floor,concrete column,shear wall and the noise measuring points of the negative floor are arranged.The vibration isolation effect is evaluated by fundamental frequency,time history curve,Fourier spectrum,1/3 octave spectrum and insertion loss.4.The floor vibration comfort and environmental vibration are analyzed.The vehicle induced human vibration comfort and environmental vibration problems of large underground shopping malls are studied through the peak value of vibration acceleration,Z vibration level and structural noise.The floor vibration comfort,environmental vibration and structural noise are compared before and after vibration isolation.