基于微观结构简化单元模型的微孔泡沫材料吸声行为研究  

Simplified Microstructural Unit Model for the Study of Sound Absorption Behavior of Microporous Foam Materials

作　　者：张钧哲 陈天宁[1,2] 朱建 刘志骁 ZHANG Junzhe;CHEN Tianning;ZHU Jian;LIU Zhixiao(School of Mechanical Engineering,Xi’an Jiaotong University,Xi’an 710049,China;State Key Laboratory for Strength and Vibration of Mechanical Structures,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学机械工程学院,西安710049 [2]西安交通大学机械结构强度与振动国家重点实验室,西安710049

出　　处：《西安交通大学学报》2021年第11期154-161,共8页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51675402,51275377)。

摘　　要：针对微孔泡沫材料的吸声系数通过其微观结构尺寸难以定量预测的难题,提出利用微孔泡沫铝的电镜扫描技术建立微孔泡沫铝微观结构的简化单元模型。利用该模型模拟微孔泡沫铝微观结构的拓扑结构,可以建立单元拓扑特征与关键的非声学参数包括静态流阻、黏性特征长度、热特征长度、曲折系数等之间的关系。在简化单元模型的基础上引入开孔率,明确了微孔泡沫材料的孔隙率和曲折度之间的关系,提高了预测微孔泡沫铝吸声系数的准确度。采用B-K阻抗管测量微孔泡沫铝试件的吸声系数,实验测量结果和理论预测结果一致。研究过程中制备的厚度小于30 mm的微孔泡沫铝试件在1100~6500 Hz频段内实现了平均吸声系数达0.8的宽频高效吸声。该研究工作可为设计、优化和制备具有更好吸声性能的微孔泡沫材料提供一定的参考。Aiming at the difficulty of quantitatively predicting the sound absorption coefficient of a microstructural foam material through its microstructure size,an SEM method is proposed to establish a simplified unit model of the microstructural aluminum foam.Using this model to simulate the topology of the microstructural aluminum foam,the relationship between the unit’s topological characteristics and the key non-acoustic parameters,including static flow resistance,viscous characteristic length,thermal characteristic length,and tortuosity coefficient,can be established.On the basis of the simplified unit model,the open porosity is introduced to clarify the relationship between the porosity and tortuosity of the microstructural foam material.So the accuracy for predicting the sound absorption coefficient of the microstructural aluminum foam is improved.The BK impedance tube is used to measure the sound absorption coefficient of the microstructural aluminum foam specimen,and the experimental measurement results are consistent with the theoretical prediction results.The specimens with a thickness less than 30 mm prepared in this research achieve broad-band and high-efficiency sound absorption,with an average sound absorption coefficient of 0.8 in the 1100-6500 Hz frequency band.This research may provide a basis for the design,optimization and preparation of microstructural foam materials with better sound absorption behavior.

关 键 词：微孔泡沫 吸声性能 简化单元模型 宽频 

分 类 号：TB34[一般工业技术—材料科学与工程] O424[理学—声学]