Study On The Preparation And Particle Damping Characteristics And Test Case Of Covering Porous Membrane Iron Tailing Sand

This dissertation presents a new conception that is supposed to be damping resource of abandoned iron tailing sand.As the filler of the particle damper,it is the key to improve its damping value.An utterly new way is provided to increase its frictional energy consumption and collision energy consumption simultaneously,which introduce a polymer layer with high viscoelasticity on the surface of iron tailing sand.In the experiment,the "C=C" lipophilic organic layer was grafted on the surface of iron tailing sand by using vinyltriethoxysilane(VTES).In the divinylbenzene-water emulsion system,the lipophilic organic layer would be covered with a layer of divinylbenzene,which would be co-polymerized to produce the covering membrane iron tailing sand(CMITS).In addition,3D printing technology was used to manufacture accurately the test case that was used to test the loss factor of the loose structure and was made by four kinds of representative resin materials.The optimal matching of the test case that is used to test the damping loss factor of the loose structure was found through the orthogonal experiment of loss energy.Test method of damping performance of loose structure by dynamic mechanical thermal analyzer(DMA-Q800)was improved and perfected.And by means of the optimal test case after verification,the change of damping loss factor of iron tailing sand damping materials was focused on the circumstance of different particle size and different filling rate.Furthermore,it was investigated to the effect of friction coefficient on the damping properties of iron tailing sand in the conditions of different materials as the modifiers.New laws and conclusions obtained in this dissertation are as follows:(1)Removing polystyrene that probably adhere to iron tailing sand by N,N-Dimethylacetamide,the covering porous membrane iron tailing sand have the peak corresponding to the peak of polystyrene tested by infrared spectrometer,which indicate the success of the grafting of polystyrene on the iron tailing sand surface.(2)Using electron microscopy to observing surface roughness and using dynamic thermal analyzer(DMA)to test the loss factor,the results indicated that the covering porous membrane iron tailing sand is inclined to have a more rough and porous surface and the maximum value of the damping loss factor is 0.31(the strain amplitude of 72.24 um),the damping loss factor improved by 40% compared to the original iron tailing sand,which is increased by 29% than that of polystyrene.(3)The damping loss factor of the covering porous membrane iron tailing sand have reached to maximum with a smaller amplitude,which indicates that the material can respond strongly to the smaller amplitude and has better damping energy consumption at a lower driving energy.(4)With the surface modification,it is known that damping characteristics of particle damping material is related to the surface friction coefficient,the particle with a larger the surface friction coefficient tend to have a larger loss factor.The friction coefficient data of covering membrane iron tailing sand(the surface friction coefficient is 0.48)and original iron tailing sand(the surface friction coefficient is 0.20)indicate that it is effective to get the friction coefficient particle changed by means of the modification of surface layer material.The friction coefficient of the covering porous membrane iron tailing sand is 0.13 higher than that of the covering membrane iron tailing sand,which demonstrates that the porous surface is propitious to increase the friction coefficient.(5)The results of Fourier infrared spectrometer test show that polystyrene is connected with the iron tailing sand by chemical bond,which is with a powerful stability.Simultaneously,the foaming agent in polystyrene can transform polystyrene foam to a rough porous structure,which is an effective way to increase the friction coefficient of the surface of the polystyrene.(6)In the orthogonal experiment,it is found that the performance of hard resin is better in relations to the soft resin,while comparing three kinds of different hard materials,it showed that grey resin material behaved the best match performance,and the size of the optimal test box wall thickness(horizontal wall thickness * vertical wall thickness)is 0.4mm*0.4mm(7)Original iron tailing sand non-surface modified are used for sand box particle damper,the maximum loss factor will appear when the filling rate is 75%,the particle size is 160 mesh-180 mesh and the amplitude is 90 ?m,the maximum value is 0.39.