一种含柱形空腔结构橡胶层的吸声机理及优化  

Acoustic absorption mechanism and optimization of a rubber slab with cylindrical cavities

作　　者：赵宏刚[1] 温激鸿[1] 杨海滨[1] 吕林梅[1] 温熙森[1] 

机构地区：[1]国防科学技术大学机电工程与自动化学院,装备综合保障技术重点实验室声学与振动组,长沙410073

出　　处：《物理学报》2014年第13期230-235,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11004249;51275519)资助的课题~~

摘　　要：采用有限元法,分析了含单层柱形空腔橡胶层(厚度20 mm)的吸声性能,表明其吸声峰频率比相同尺寸的球形空腔低,这与单个柱形和球形空腔的单极共振频率相对应,通过谐波散射分析证实了空腔单极共振引起的能量耗散增强了声波的吸收。采用能量耗散功率及位移场分布,对柱形空腔结构的吸声机理进行了深入分析.其次,在钢背衬条件下分析了横波损耗因子对橡胶层吸声特性的影响,并采用遗传算法对含不同尺寸柱形空腔橡胶层在1.5—10 kHz频段上的吸声特性进行了优化,获得了较好的宽频吸声效果.The finite element method is introduced to investigate the absorption of a rubber slab （20 mm thick） with one layer of cylindrical cavities. It has a lower frequency absorption peak than that with spherical cavity in the same size, which is determined by the monopole resonance of cavities. Analysis of partial wave scattering verifies that the absorption peak is induced by the monopole resonance. Power dissipation density and displacement pattern of one unit cell is used to clarify intuitively the absorption mechanism of the cavity. Then the effect of damping of transverse modulus on the absorption is investigated under the condition of a steel backing. Both the physical and structural parameters of the rubber slab are optimized by a genetic algorithm for favorable absorption from 1.5 to 10 kHz.

关 键 词：MIE散射 有限元法 柱形空腔 吸声 

分 类 号：O422.4[理学—声学]