关键词: 柱状长骨, 频散, 激发强度, 超声导波, 横向各向同性,  

Abstract: 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 parameter \%ε\% 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 parameter  \%δ\% decreases, 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 frequency  50 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.

Key words: excitation intensity, ultrasonic guided wave； dispersion, cylindrical long bone, transversely isotropic