黏弹性吸声材料复弹性模量优化研究

针对黏弹性材料吸声效率问题,利用分层介质声传播理论和数值算法优化了不同物理条件下材料的复弹性模量。采用参数等效的方法分析了含气泡黏弹性材料的声学特性,并给出了此种材料优化后的弹性模量曲线。根据物理模型计算了一定边界条件下材料复弹性模量等吸声系数曲线,得到了几种背衬条件下黏弹性材料吸声系数大于0.8的弹性模量和损耗因子范围。研究表明调节黏弹性材料的复弹性模量可以有效提高材料的吸声性能,吸声系数大于0.8时其弹性模量和损耗因子范围在不同背衬条件下差异较大,发现一定厚度的钢背衬会降低调控复弹性模量的难度,对含气泡黏弹性材料的计算也可得到类似结果。 

An investigation on the optimization of complex elastic modulus for viscoelastic absorption materials

Based on wave propagating theory of multilayered medium and the optimizing algorithm, the complex elastic modulus of viscouselastic materials are optimized with different physical conditions in order to improve material absorption performance. The absorption performance of bubbled viscoelastic materials is computed and the curves of the optimized elastic modulus are plotted as well. Isoclines of absorption coefficient on complex elastic modulus of absorption materials are presented with certain boundary conditions . Assuming the absorption coefficient is larger than 0.8, the scope of elastic modulus and loss factor of the viscoelastic materials with different boundary conditions are given and discussed. The results show that the sound absorption performance can be improved effectively by adjusting complex elastic modulus of viscoelastic materials. The scope of complex elastic modulus is found to be very sensitive to the boundary conditions while the absorption coefficient is larger than 0.8. The difficulty of adjusting complex elastic modulus can be reduced with certain steel backing. These conclusions are applicable to the case of bubbled viscoelastic materials.