Study On Performance Of Metro Rail Sound-absorbing Board

The subway，as a means of urban rail transportation, is very favourabletransportation tool of today’s big city passenger traffic，but with the constructionvolume increased year by year，the rail noise and subway station noise have becomethe key factors restricting the sustainable development of it. Metro Railsound-absorbing board has good sound absorption performance，the sound absorptionprinciple is that sound-absorbing board has a large number of internal connected tinygaps and holes, these holes has fine structure and communicating with each other。Acoustic waves incident on the Surface, along the pore structure into thesound-absorbing board, excited vibrations of the air in the internal pore structure, theair and the wall friction produces heat conduction effect, due to air viscosity, producesviscous resistance in the pore structure, the vibration energy (acoustic waves) can beconsumed continuously transformed into heat, so that the acoustic wave attenuation,achieve the purpose of reducing noise. foreign Engineering practice shows: usingceramic sound-absorbing board is one of the main measures of noise control，indoorreverberation sound in general can be reduced by5~10dB by sound-absorbingtreatment. This paper mainly studies the mechanical properties, the sound absorptionproperties of sound-absorbing made by mixing proportion adjusting,and studysSound-absorbing board mould design combined with specific engineering, verifingthe sound-absorbing board structure design meet the design strength requirements anddaily maintenance repair operations. The main research work as follows：（1）On the basis of the packing density of ceramisite, analysis compressivestrength, flexural strength and The sound absorption coefficient of standing wave tubeacoustic of sound-absorbing block in cases of density Less than900kg/m3、900kg/m3~1100kg/m3and greater than1100kg/m3，determines the mixing proportionof sound-absorbing board with independent patent and analyses the productionprocess.（2）Based on track vibration and vibration control laboratory of Beijing jiaotonguniversity，Produces the orbital sound-absorbing board meeting the sleeper forms andcarries out sound-absorbing test，the experiment analyses the noise reduction effect oftunnel wall test point and Ballast point under different operating conditions，Theresults show that：noise reduction coefficient reaches0.85, the sound absorptionproperties of grade Ⅰ.(3) Combined with the sleeper form of sound-absorbing which is used for Sound absorption test and25meters sleeper form of one project, carries out sound-absorbingboard structure design and verify the practicability of the sound-absorbing boardstructure design through the mould design and ANSYS simulation.