摘要
由于黏弹性材料对入射声波具有较为明显的吸收作用,与常见的弹性材料相比,黏弹性材料中波的传播比较复杂。为了研究其在低频超声作用下的不同厚度黏弹性响应特征,基于黏弹性介质中波传播的控制方程,得到了波传播规律中的理论公式;并在此基础上,分别仿真了材料厚度远小于、略小于、等于、略大于以及远大于所选低频超声波长的五种情况,并据此分析了不同厚度下此种黏弹性介质的应力情况。仿真结果表明:1)随着介质厚度的不断增加,黏弹性材料的黏性随之增大,所选低频超声穿过试块时,在试块相同位置的探针点所接收到的响应也随厚度增加而衰减,衰减态势呈线性。2)在材料厚度与所选低频超声波长差异过大时,将导致仿真无波形或者波形无变化等极端情况。由此可知,随着厚度的增加,细微观结构产生的黏性也随之线性增加,对于低频超声吸收作用不可忽略。
Due to the obvious absorption of viscoelastic materials to incident sound waves,the wave propagation in viscoelas⁃tic materials is more complex than that in common elastic materials.In order to study its viscoelastic response characteristics of dif⁃ferent thickness under the action of low-frequency ultrasound,based on the control equation of wave propagation in viscoelastic me⁃dia,the theoretical formula of wave propagation law is obtained.On this basis,five cases in which the material thickness is far less than,slightly less than,equal to,slightly greater than and far greater than the selected low-frequency ultrasonic wavelength are simulated respectively,and the stress of this viscoelastic medium under different thickness is analyzed accordingly.The simulation results show that:with the continuous increase of the thickness of the medium,the viscosity of the viscoelastic material increases.When the selected low-frequency ultrasound passes through the test block,the response received at the probe point at the same posi⁃tion of the test block also attenuates with the increase of the thickness,and the attenuation trend is linear.When the difference be⁃tween the material thickness and the selected low-frequency ultrasonic wavelength is too large,the simulation will result in no wave⁃form or no change in waveform and other extreme cases.It can be seen that with the increase of thickness,the viscosity produced by fine microstructure will also increase linearly,and the low-frequency ultrasonic absorption effect cannot be ignored.
作者
康鑫
王黎明
聂鹏飞
韩星程
武国强
马文
KANG Xin;WANG Liming;NIE Pengfei;HAN Xingcheng;WU Guoqiang;MA Wen(Shanxi Provincial Key Laboratory of Information Detection and Processing,North University of China,Taiyuan 030051)
出处
《舰船电子工程》
2023年第12期105-108,212,共5页
Ship Electronic Engineering
基金
国家自然科学青年基金项目(编号:62203405)
山西省重点研发计划(编号:2022ZDYF079)
山西省应用基础研究计划(编号:20210302124545)资助。
关键词
低频超声
黏弹性材料
有限元仿真
low-frequency ultrasound
viscoelastic materials
finite element simulation
