Numerical analysis of the effects of viscoelastic constitutive relation on dynamic characteristics of human ear
Tian Jiabin1, Rao Zhushi1, Ta Na1, Xu Lifu1, Huang Xinsheng2
1. Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240;
2. Zhongshan Hospital A?liated to Fudan University, Shanghai 200032
摘要为了分析中耳软组织的粘弹性材料特性对于人耳系统动力学特性的影响，建立了包括外耳道、中耳和耳蜗的整耳有限元模型。外耳道和中耳模型应用微CT扫描和逆向成型技术建立，耳蜗采用双腔导管形式的简化模型。基于该模型，中耳部分软组织的材料属性采用线性粘弹性，用于表征动态分析中的能量损耗。于外耳道施加90 dB SPL声压，从而模拟正常人耳的声激励，并在计算中考虑外耳道气体、中耳固体和耳蜗流体的多场耦合作用。中耳的结构响应包括了鼓膜脐部与镫骨底板位移和镫骨底板速度传递函数，耳蜗的流体压力响应则用于计算中耳压力增益、耳蜗输入声阻抗和耳蜗压力逆向传递函数。结果表明，考虑粘弹性特性后，人耳系统的动态响应参数相比线弹性有了一定程度的改善，特别是在高频段的提升较为明显，与实验测量数据具有更好的匹配效果，说明了粘弹性本构关系的引入在人耳动力学建模中的必要性。
Abstract：To analyze the effect of viscoelastic properties of middle ear soft tissues on the dynamic characteristic of the human ear system, a finite element (FE) model of the human ear consisting of the external ear canal, middle ear and cochlea was developed in this study. The geometric model of the external ear canal and middle ear was constructed via micro-CT scanning and reverse engineering technology, and the cochlea was simplified as an uncoiled, two-chambered and fluid-filled duct. The viscoelastic material behavior was introduced into middle ear soft tissues to represent the energy dissipation in dynamic analysis. Multiphysics coupled analysis was conducted on the model which included the air in the ear canal, the fluid in the cochlea and middle ear structures. Then a sound pressure of 90 dB SPL was applied at the ear canal to simulate the sound stimulus of normal human ear. Middle ear structural responses such as movements of the tympanic membrane and stapes footplate in response to the sound stimulus were derived from this model. Meanwhile, by calculating the pressure of the fluid in the cochlea, the sound pressure gain across the middle ear, cochlear input impedance and reverse pressure transfer function of cochlea were also obtained. The results show that, employing viscoelastic properties of middle ear soft tissues improved the dynamic responses of the human ear system as compared with linear elasticity, especially at the high-frequency range. The better agreements between the model and experimental data in the literature illustrate the necessity of considering viscoelasticity for dynamic modeling of the human ear.
田佳彬,饶柱石1，塔娜1，许立富1，黄新生2. 粘弹性本构对于人耳动力学特性影响的数值研究[J]. 振动与冲击, 2015, 34(22): 74-81.
Tian Jiabin1, Rao Zhushi1, Ta Na1, Xu Lifu1, Huang Xinsheng2. Numerical analysis of the effects of viscoelastic constitutive relation on dynamic characteristics of human ear. JOURNAL OF VIBRATION AND SHOCK, 2015, 34(22): 74-81.
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