Characteristics And Spectrum Evaluation Of Outside Noise On Asphalt Pavements As Vehicle-tire-road Coupling

Traffic noise is coupling produced by 'vehicle-tire-road'.Most of current 'tire-road'research about 'tire-road' focus on the tire object,while road as the carrier of the 'vehicle-tire-road' coupling system is only in a subordinate position,and not be in-depth consideration.In order to study the effect of the surface texture of asphalt pavement on road noise,the paper presents a totally new method to simulate the asphalt pavement noise in the'vehicle-tire-road' system.Firstly,use scanner to obtain the apparent texture of AC,SMA and OGFC asphalt pavement,the three most common asphalt pavements.Then apply Matlab to deal with messy scatters,therefore we can get the available three-dimensional spatial coordinates of the pavement nodes,to provide a basis for the construction of three-dimensional pavement model.Secondly,build a complete three-dimensional pavement model in Adams,do the full-vehicle analysis,simulate the excitation of suspension and body on tire,and output the vertical displacement curve of tire.Compare effect of the three kinds of asphalt pavement,OGFC the largest,SMA followed,AC minimum.Changing the friction coefficient of the pavements and vehicle speed,it is found that the speed has a significant effect on the vertical displacement of the tire,while the friction coefficient mainly affects the lateral displacement of the tire and has no obvious effect on the vertical displacement.Next step is to build an "air-tire-pavement" three-dimensional model for air pumping noise study and a model for vibration noise study in Abaqus finite-element software.Apply the mandatory vertical displacement of the left front tire got from Adams to the tire by"Abaqus-Amplitude",to simulate the sound pressure on the three kinds of asphalt pavement.The results show that OGFC has the best effect on reducing noise,about 3dB lower than AC,and the greater the noise will be when speed increases.Vibration noise increases 0.7dB and pump noise increases 0.6dB along with speed increasing by each 10km/h.Finally,use Matlab to achieve fast Fourier transform,which could transform the time domain diagram of noise signa into spectrum diagram.The spectrum shows that,AC road noise frequency is mainly concentrated in the 1000Hz-1800Hz,while SMA pavement and OGFC pavement are 900Hz-1800Hz and 750Hz-1700Hz.AC road vibration noise frequency is mainly concentrated in the 500Hz-800Hz,while SMA pavement and OGFC pavement are 400Hz-800Hz and 300Hz-700Hz.The faster the vehicle speed is,the frequency distribution of noise goes to the high frequency under the same conditions.The results of this paper could be applied to noise reduction optimization of asphalt pavement structure in the future.