Research Of A Constrained Damping Structure Based On A New Type Of Viscoelastic Material And ANSYS Analysis

This paper is based on the railway constructed in Qingdao now, studied a new type ofviscoelastic material by FTIR, DSC and DMA. Then tested the elastic modulus andpassion ratio of motar plate and steel respectively. Using different methods to test thevibration isolation performance of constrained damping structure based on mortar andsteel. Combined with ANSYS analysis, studied the importance of constraineddamping structure on vibration isolation. The results are as following:First of all, FTIR result shows that, this new viscoelastic damping material hasvibration absorption peak in1670cm-1~1800cm-1, and there is no NCO vibrationabsorption peaks, so it shows that the sample was reacted completely. DSC researchproves that, the glass transition temprature is around50℃, and it will decomposewhen the temperature reached to240℃. DMA shows that, the loss factor in66Hzappeared a minimum, when frequency exceed165Hz, tanδ>0.3, and the higer thefrequency, the lager the loss factor. In high frequence, the temperature whentanδ>0.3is in agreement with the environmental temperature. The performance isbetter.Secondly, according to the study of the vibration isolation of constrained dampingstructure based on motar and steel, the elastic modulus of motar is2.69e10Pa, poissonratio is0.3; The elastic modulus of steel is2.01e11, poisson ratio is0.28. Whendamping layer are1mm,2mm,3mm,4mm, analysis the constrained dampingstructure’s vibration isolation performance by hitting vibration test. The result showsthat, in-250Hz~3500Hz frequency range, the vibration isolation performance of1mmdamping layer’s constrained damping structure is the best. Through cantilever beamtest studied the vibration isolation performance of constrained damping structurebased on steel as damping layer are1mm,1.5mm,2mm. The result shows that theircorresponding structure damping ratios are17.8660%、19.9202%、20.6638%. So the2mm is best. Because the restrict of experiment condition, the damping layer can’t bethinner or thicker, so used ANSYS to further analysis the law of vibration isolationperformance as constrained damping structure changed. At last, through ANSYS, analysis these two kinds of constrained damping structure bymadal analysis and transient analysis. The modal analysis obtained the resonancegraphic and resonant frequence of constrained damping structure based on motar andsteel. The transient shows that, when the damping layer is1mm, the constraineddamping structure based on motar’s vibration isolation performance is best; And whendamping layer is2mm, the constrained damping structure based on steel’s vibrationisolation performance is best.