Preparation And Research On Acoustic Charicateristics Of The Sound Abosrption Material Based On Polymer Micro-Particles As Well As Computer Simulation

In this paper, a novel kind of sound absorption materials assembled with polymer micro-particles was prepared, among which PU foam with certain geometry vacuum severed as bound materials. Polymer micro-particles with different structures, size and size distributions were synthesized by suspension, dispersion and emulsion polymerization. The sound absorption characteristics of the materials are discussed and the experimental investigation of acoustic properties has been carried out in the impedance tube (B&K 4026) according to transfer function method. By using Discrete Element Method (DEM), a new computer simulation method is also presented to study the sound absorption mechanism of the material here.Experimental results show that the material possesses its characteristic frequency band where the average sound absorption coefficient of the material is 0.4 and the maximum is up to 0.92. Compared to PU foam, the material needs less thickness for achieving the same effect of soundabsorption. Consequently, the results demonstrate that the acoustic behavior of the material, and farther the sound absorption ability are apparently been influenced by the multilevel microstructures and properties of polymer micro-particles.The classic models are commonly applied to polymer porous materials but not suitable to the material in this paper. Although the prediction to sound absorption coefficient of the material by Artificial Neural Networks model (ANN) is quite good, no more detail information can be found from this model and therefore the DEM model for the material is developed. On the basis of the model, a calculation programs using MATLAB have been created and moreover, the computer simulations for evolution the energy dissipation mechanism of polymer micro-particles have been performed. Then preliminary research on the sound absorption performance of the material is conducted. Theoretical analyses indicate that the sound absorption provided by the material mainly consist of two parts: the conventional vsico-thermal mechanism between polymer particles and air and the integrated kinetic loss of particles with motion under external stress.