Research On Numerical Simulation Of Asphalt Pavement Noise Based On Tire/Road Coupling

In recent years,with the steady development of the highway industry,pollution caused by traffic noise in the environment has become more and more serious,which not only causes people’s mood swings but also harms people’s health.The establishment of low-noise asphalt pavement is a noise reduction measure proposed from the root cause of noise.The current research mainly relies on a large number of indoor and outdoor tests,which consumes a lot of manpower,material and financial resources.The results are also easily affected by equipment and environment.It is difficult to give a reasonable explanation and mechanism analysis of tire/road noise.Therefore,based on the basic theory of acoustics,this thesis establishes a numerical simulation model of asphalt pavement noise under tire/road coupling through finite element software,and studies the influence of vehicle driving conditions,tire patterns,pavement structure and other factors on asphalt pavement noise.The correlation analysis method clarifies its main influencing factors,and builds a tire/road noise prediction model based on BP neural network.Finally,optimize the design of the asphalt mixture to achieve sound absorption and noise reduction performance while having good road performance,relying on physical engineering to verify the noise reduction effect and simulation results.It is expected to provide a new effective analysis method for the optimization of asphalt pavement noise reduction,and it has important practical significance to accelerate the research and development of low-noise asphalt pavement.The specific research content and conclusions are as follows:First,based on the acoustic wave motion equation,the equation of state and the continuum equation,the basic acoustic calculation equation-Helmholtz wave equation is derived,and its finite element solution method is given.The source and generation mechanism of tire/road noise are clarified in detail,and it is confirmed that when the vehicle is driving at high speed,the main noise source is the noise generated by the coupling effect of tire/road,among which vibration noise and pumping noise are generated by tire/road noise.The most important noise mechanism provides a theoretical basis for establishing a numerical model.Secondly,with the aid of Abaqus finite element software,the model was reasonably simplified,and three-dimensional pump noise and vibration noise models under tire/road coupling were established respectively,and Virtual lab acoustic finite element software was used to establish an analysis of the sound absorption performance of asphalt mixture.The simulation model synthesizes the total sound pressure level according to the principle of sound wave superposition.By comparing the simulation results of the model with the measured data on site,the cumulative frequency of the data with a relative error of less than 10% reached 90%,and the average value of the relative error was only 4.8%.The simulation effect was good.Thirdly,with the aid of the established simulation model,considering the three aspects of vehicle driving state,tire pattern,and road structure,the system analyzes the influence of various factors on tire/road noise,and uses the gray correlation theory analysis method to judge the impact of different parameters.The degree of influence of noise is selected and its main influence factors are selected based on the BP neural network to construct a tire/road noise prediction model.Studies have shown that with the increase of vehicle speed,tire tread groove depth,and structure depth,the noise shows an increasing trend.The noise is mainly negatively correlated with porosity and material damping ratio;while the tire tread groove width and load have a negative effect on noise.The impact is not obvious.The primary and secondary order of the influence of each parameter is: speed> damping ratio> void ratio> tire tread groove depth> road thickness>structure depth> tread groove width> load.In order to ensure that the model has high computational efficiency and minimizes errors,the number of neurons and other basic parameters are optimized.In the end,the best mean square error of the tire/road noise prediction model is only 0.0019047,and the regression coefficients of each sample are all above 0.95,which fits well with the finite element calculation results.Finally,from the perspective of raw materials and grading,in order to make the asphalt pavement material have good noise reduction performance and road performance,optimize the design of the thin layer overlay mix ratio based on the noise reduction function.The mechanical performance and high temperature performance of the asphalt mixture were evaluated through indoor tests,and the noise reduction performance of the thin-layer overlay was tested and analyzed on-site based on the physical engineering implemented at the S428 Jiangtu Road section of Wuling Mountain in Fuling District.Research shows that it has large internal damping,good vibration reduction effect,and excellent high temperature stability and low temperature crack resistance.Through the field test,it is found that compared with the ordinary AC-13 asphalt pavement,the average noise reduction can reach 6.7d B(A),and the noise reduction effect is obvious.The actual measurement results are compared with the predicted results,and it is verified that it is feasible to predict the noise by means of numerical simulation in engineering.