超声振动测量的模型分析  

Model Analysis of Ultrasound Vibrometry

作　　者：陈科[1] 林江莉[1] 尹光福[1] 郑翊 

机构地区：[1]四川大学生物医学工程系,四川成都610065 [2]圣克劳德州立大学电气与计算机工程系,明尼苏达圣克劳德56301

出　　处：《四川大学学报（工程科学版）》2012年第4期209-213,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(30970781);高等学校博士学科点专项科研基金资助项目(20100181110002)

摘　　要：基于Zener模型的超声振动检测方法可无损地定量测出材料或组织的剪切力学性质。其克服了Voigt模型不能描述应力松弛过程的局限性,能够准确地表达黏弹性介质的动态响应。基于Zener模型的本构关系和波动方程,推导出了基于此模型的剪切波传播速度公式,该公式将剪切波的相速度和介质的剪切力学性质关联了起来。在获得剪切波在多个频率上速度的前提下通过数学方法估计出介质的剪切模量。将凝胶模型和橡胶管作为实验对象,获得剪切波在两者中的传播速度,分别用Voigt模型和Zener模型对速度值进行拟合,结果均显示Zener模型更加适合于二者的描述,为材料检测和组织定征提供了更为准确的方法。Voigt model based ultrasound vibrometry method can be utilized to measure shear mechanical properties of materials or bio- logical tissue quantitatively and invasively. But Voigt model cannot describe stress relaxation of medium. In order treat this problem, a more generalized model, Zener model, was used to represent complex viscoelastic behavior of isotropic and incompressible viscoelastic medium. Based on Zener model, the shear wave propagation velocity was derived from the wave equation and the constitutive relation of Zener model. The shear modulus was estimated from velocity by mathematical method. Shear wave velocities in gelatin and rubber were obtained. Voigt ~nd Zener model were utilized to fit the velocities, respectively, and the results demonstrated that Zener model is better for characterization.

关 键 词：超声振动测量 黏弹性 Zener模型 

分 类 号：O426.9[理学—声学] R318.6[理学—物理]