Study On Performance Of Damping Materials And Constrained Damping Multiple Constrained Damping Structure

Constraint damping structure has a strong ability of anti-vibration noise reduction, especially constrained damping structure with new type of polymer damping materials, at present, the main research results and application are given priority to single constraint damping structure, in some special projects, single constraint damping structure is often difficult to meet demand, so, the research on noise and vibration reduction of multi-layer constraint damping structure is very necessary.Against the background of Qingdao subway test section,viscoelastic damping materials and multiple constraint damping structure are studied. Specific experimental result about the following:(1) Firstly,studing the density of damping materials, the drying time, solid content, mechanical properties, hardness and dynamic mechanical properties.Basic performance experiment results show that the density of viscoelastic damping material is 0.9652; Gel time is 170.7s, table dry time is 13.3min, work time is 32min; Solid content as high as 94.06%; The tensile properties of the materials with the increase of curing days increase gradually and finally stablilized at about 7.62Mpa; Elongation at break reduced gradually with the increase of curing days and eventually stabilized at about 358%; Hardness is gradually increasing with the increase of curing days, 15 days after basically stable at around A57.In given conditions, a frequency energy storage modulus of viscoelastic damping materials with the increase of temperature decreases, at a certain temperature, material storage modulus increase gradually with the increase of frequency, and material loss factor with the increase of temperature decrease after increased first, and under the influence of the temperature and frequency peak positions, different material loss factor.(2)Secondly, through the study of multiple constraint damping plate ceramic tile,using Dasp analysis software in the spectrum analysis module, the double spectrum analysis module and time-domain analysis module,analysis the damping properties of constrained damping structure with different layers.The research results showthat with the increase of constrained damping layer constraint damping structure, the composite loss factor increase gradually, but the increase rate decreases gradually, followed by 0.054, 0.052, 0.037, after reaching 3 layers, loss factor increase amplitude decreases obviously. Vibration acceleration total level with the increase of damping layer gradually decreases, and, in turn, 142.20 d B, 134.49 d B, 131.06 d B, 134.49 d B, after reaching 3 layer, the increase amplitude decreased significantly. Comprehensive analysis, 3 layer damping structure get the most ideal damping performance.(3)Through the above test, compares the Multiple constraint damping structure with the single constraint damping structure, the study research shows that the thickness of the same damping materials, 3 1 mm damping layer constraint damping structure compared with 1 3 mm damping layer constraint damping structure, the first-order compound loss factor increased by 0.039, 1.64 d B vibration acceleration level decreased; 7 1 mm damping layer constraint damping structure compared with 1 layer 7 mm constraint damping structure damping layer, first order composite loss factor increased by 0.051, vibration acceleration level decreases 4.63 d B.Therefore,multiple constraint damping structure damping performance is better than that of single constraint damping structure.(4)Finally, through the experiment study of dampingwall and concrete wall, using Dasp analysis software in the spectrum analysis module, the double spectrum analysis module and time-domain analysis module,analysis the damping properties of damping wall and concrete wal and the changes of damping wall′s damping properties with the damping layers change.The research results show that the damping loss factor of damping wall is significantly higher than the concrete wall. Take the mean value of loss factor of each layer as the yardstick, damping wall layers’ first-order loss factor is 0.197, concrete wall’s first-order loss factor of each layer is 0.143, compared to the concrete wall, damping wall first-order loss factor increased by 0.054 as a whole. Compared with concrete wall, damping wall’s first layer in the total vibration acceleration level value decreases 2.75 d B, second layer decreases 12.38 d B, third layer decreases 6.32 d B, seventh layer decreases 6.67 d B.Take damping wall’s right side as example, one, three, five, seven layers of total vibration acceleration level value are 129.88 d B, 119.87 d B, 118.37 d B, 117.82 d B,with the increase of damping layer, total vibration acceleration level value decreased 10.02 d B, 1.5d B, 0.55 d B. Damping wall’s decay time is less than concrete wall, each layer of the vibration amplitude were lower than that of concrete wall, and with the increase of damping layer damping wall decay time also gradually reduced.Based on the above studies, the performance difference between multiple constraint damping structure and single constraint damping structure is obtained, determines the optimum damping layers of constrained damping structure layer, provide basic data for the application in the practical and theoretical support.