柱状长骨中的纵向超声导波频散和激发强度  

Dispersion and Excitation Intensity of Longitudinal Ultrasonic Guided Wave in Cylindrical Long Bone

作　　者：周久光[1,2] 张洪武 张碧星[3] 崔志文[1] 

机构地区：[1]吉林大学物理学院,长春130012 [2]北华大学基础医学院,吉林吉林132021 [3]中国科学院声学研究所,北京100190

出　　处：《吉林大学学报（理学版）》2017年第6期1575-1581,共7页Journal of Jilin University:Science Edition

基　　金：国家自然科学基金(批准号:41474098;11134011);声场声信息国家重点实验室开放基金(批准号:SKLA201608)

摘　　要：用一个内充水、外覆水层的横向各向同性柱壳模拟长骨,将环状声源置于长骨外流体层中,数值模拟和分析导波的群速度和激发强度,并考察各向异性参数及长骨内半径对导波频散和激发强度的影响.结果表明:当长骨从各向同性变为横向各向同性时,高阶纵向导波的群速度峰值明显增大;当各向异性参数ε减小时,高阶纵向导波的群速度峰值明显减小,且群速度曲线向低频区域移动;当各向异性参数δ减小时,高阶纵向导波的群速度峰值明显增大;当长骨内半径增加,在低频50kHz附近时,最低阶纵向导波L01的群速度明显减小,激发强度明显增强;最低阶和第二阶纵向导波模式可分别用于检测长骨的厚度变化及各向异性特征.A transversely isotropic cylindrical shell inside filling with water and outside surrounded by a water layer was used to simulate the long bone.The circle acoustic source was located in outer water layer of long cortical bone.The group velocities and the excitation intensities of the guided waves were numerically simulated and analyzed,and the influence of the anisotropic parameters and the inner radius of long bone on the dispersion and the excitation intensity of guided wave were investigated.The results show that when long bone changes from isotropic into transverse isotropic,the group velocity peaks of high order longitudinal guided wave increase obviously;when the anisotropic parameterε decreases,the peak value of group velocity of high order longitudinal guided wave decreases obviously,and the group velocity curve moves to the low frequency region;when the anisotropic parameterδdecreases,the peak value of group velocity of high order longitudinal guided wave increases obviously;when the inner radius of long bone increases,and near the low frequency50 kHz,the group velocity of the lowest order of longitudinal guided wave L01 decreases obviously,and the excitation intensity enhances obviously;the lowest order and the second order longitudinal guided wave can be used to detect the change of thickness of the long bone and anisotropic characteristics,respectively.

关 键 词：横向各向同性 柱状长骨 超声导波 频散 激发强度 

分 类 号：O426.2[理学—声学]