| High-speed railway has become a postcard of china,along with the rapid development of high-speed railway,the railway will inevitably go through life and office areas,causing a serious plague to people's life,The sound barrier of high speed railway is widely used along the railway because of its good noise reduction effect,convenient installation and economic durability.The paper mainly based on the finite element analysis software ANSYS,using the separation method to study the dynamic response of the high speed railway side sound barrier.Through the finite element software ANSYS,the model of the vertical splank sound barrier of high speed railway is established and the modal analysis is carried out.According to the code for design of railway bridge and culvert,the natural wind load is calculated,and the sound barrier model is acted on the sound barrier in the way of its static load.Then according to the calculation formula of fluctuating wind load obtained online measured by Germany,APDL language of ANSYS will be the fluctuating wind load is loaded into the sound barrier surface,dynamic sound barrier structure response,time domain analysis,and then use the fast Fu Liye transform matlab analyzed its frequency spectrum;Finally,the response of sound barrier under the superimposed load of natural wind and pulsating wind is discussed,and the loading mode is the same as the loading mode of natural wind load.In view of the main function of the sound barrier is noise reduction,the paper discusses the selection of the material for the sound barrier filler,and then tests the sound barrier made of the selected filler material in the semi noise chamber.The noise reduction effect of sound barrier under different working conditions is obtained,which will provide a loan for the actual application of sound barrier in the field.Here's the conclusion of the work above:[1]through the modal analysis of a span and eight span two kinds of sound barrier model,it is found that the two natural frequency of the difference was that the sound barrier between the panel and the column,as well as between the panel and the panel will be mutual influence,in order to ensure the accuracy of the simulation analysis,should choose the appropriate length of the response of sound barrier dynamic analysis.[2]According the calculation formula is given by German Railway and provided suggestion to the China harmony EMU c_P value.The mileage curves of the pulsating wind load of the German ICE train and the CRH2 and CRH3 type trains in China are plotted respectively,three models of fluctuating wind load value of the size of the order(from large to small in turn)CRH2,CRH3,ICE3,CRH3 was selected as the incentive models.[3]Based on the"railway bridge design code"formula,the paper selected 8 grade wind(20m/s),9 grade wind(24m/s),wind 10 level(28 m/s),wind 11 level(32 m/s)calculation of wind natural wind load value,and then from the outside to static loading way effect on sound barrier model.[4]The dynamic response of the sound barrier column under the natural wind load is about symmetrical distribution,and the displacement of the middle column is the largest.The higher the series of typhoon,the greater the peak displacement peak,the greater the difference of the peak displacement between the two adjacent typhoons.In the aspect of sound barrier height,the higher the height is,the larger the peak displacement at the top of the column is,and the difference between the two adjacent typhoons is also increasing.Therefore,the higher the height of the sound barrier in the design of sound barrier,the higher the stiffness,stability and safety requirements.[5]The last second columns of sound barrier structure under the fluctuating wind load of the whole structure is prone to fatigue damage,the maximum dynamic response of touch panel in the panel and the bottom second columns at the top of the place,so the sound barrier design should focus on strengthening the reciprocal of second columns and second bottom panel setting and stability column top contact point.[6]The speed and the center distance are the main influencing factors of sound barrier structure security,this paper analyzes the different center distance,different speed power under the sound barrier structure in response to the situation,results show that increases with the increase of train speed dynamic response of sound barrier structure,and decreases with the increase of the distance from the center,through the polynomial fitting,the sound barrier column panel and the dynamic response and the train speed is two times the growth curve,the fitting degree was more than 0.9.[7]Through the fast Fu Liye transform of Matlab,the frequency spectrum of the displacement peak of the structure is analyzed.It is shown that the amplitude of the structure increases with the increase of the running speed of the train.But the peak frequency is basically within 10Hz,and the peak value is mainly about 2-8 Hz.Through the modal analysis of the sound barrier structure,we know that the fundamental frequency is above 12Hz,so the structure will not resonate.In order to ensure the safety of the sound barrier structure,the natural frequency of the structure should be set to above 15Hz when designing the sound barrier,so that the noise barrier will be destroyed due to the resonance,so as to ensure the safety of the train operation.[8]Under the action of superimposed load,when the sound barrier height is 3.15m,the displacement of the top of the column is close to the limit of fatigue failure.Therefore,when the typhoon comes,the train should be stopped to ensure the safety of railway traffic and personnel.[9]By comparing the natural wind load,the pulsating wind load and the two superposition load on the sound barrier,the top displacement response of the vertical column is compared and analyzed,It is found that the peak displacement at the top of the column is not equal to the sum of the peak values of the negative displacement when the natural wind and the fluctuating wind act alone,that is to say,it is not a simple superposition,but rather a coupling action.Therefore,there must be a certain safety reserve when the sound barrier is designed,and the design should be carried out with the most unfavorable load combination.[10]The sound absorption barrier is better than the reflected sound barrier,and it is economical and practical.The experiment of sound absorption barrier in the semi silencer shows that the lower the height of the sound source,the better the effect of noise reduction.The sound source height in 0.7 meters than the noise reduction of sound source 1.5meters about 2db.The insertion loss of the size and sound from the sound barrier distance(acoustic distance),acoustic point distance is greater insertion loss.The comparative analysis shows that the acoustic distance of 1.67 meters of insertion loss than 3.3m when the distance between the acoustic point of insertion loss of about 10db. |
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