黏弹性材料的动态力学特性及其对覆盖层吸声性能的影响  

Dynamical mechanical property of viscoelastic materials and its effect on acoustic absorption of coating

作　　者：吕林梅[1] 温激鸿[1] 赵宏刚[1] 温熙森[1] 

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

出　　处：《物理学报》2014年第15期225-230,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：本文利用标准化动态力学测量手段获得了某种高分子聚合物的动态杨氏模量,并根据时温等效原理对动态杨氏模量与声学测量在频段上的差异加以分析和转换,得到了500—7500 Hz频率范围内该黏弹性材料杨氏模量随频率变化的特性.基于所测得动态杨氏模量,采用有限元方法分析了均匀黏弹材料的吸声性能,并将仿真结果与样品声管实验数据进行对比,验证了测试所得参数的准确性.进一步仿真分析了含有局域共振结构的声学覆盖层吸声性能,并讨论了黏弹性材料的动态特性对其吸声性能的影响,提出了改进水声覆盖层低频宽带吸声特性的建议.Viscoelastic macromolecular materials are widely used in underwater acoustic fields because of their favorable acoustic performance. Dynamical mechanical properties of viscoelastic materials, such as Young＇s modulus, shear modulus, and relevant loss factors, are important in the forecast of acoustic properties, which connect acoustical design of underwater coating with materials prescription design. Dynamic Young＇s modulus of some macromolecular materials is measured with dynamic mechanical apparatus （DMA）, and then the basic acoustic parameters are expanded from a narrow band to a broad band by using principles of time-temperature superposition （TTS）. When applying the basic parameters to calculating characteristics of the uniform layer sample by using the finite element method, a reasonable agreement of sound absorption coefficients is obtained between the calculations and measurements in the acoustic pipe. Furthermore, the underwater acoustic absorption properties of the coating with a local resonant structure are discussed. Finally, some suggestions are given about how to improve the underwater absorption performance at low frequencies.

关 键 词：水下声吸收 局域共振结构 动态力学性能 

分 类 号：O427[理学—声学]