Hu Wenxiang, Qian Menglu
Institute of Acoustics, Tongji University, Shanghai 200092, People's Republic of China.
Ultrasonics. 2006 Dec 22;44 Suppl 1:e1187-90. doi: 10.1016/j.ultras.2006.05.068. Epub 2006 Jun 5.
The excitation and propagation of the acoustic waves in an elastic cylinder are studied by laser ultrasonics both theoretically and experimentally. The theoretical analysis of the two-dimensional acoustic field excited by a pulsed laser line source impacting on the generatrix of an elastic cylinder is presented. The dispersive properties for both cylindrical Rayleigh wave and the higher modes--whispering gallery (WG) modes are analyzed in detail. The numerical transient displacement waveforms for a detecting point located another terminal of the cylinder diameter opposite the source are calculated. The experimental excitation and detection of the acoustic waves in an aluminum cylinder are carried out on a laser ultrasonic system, which mainly consists of a Q-switched Nd:YAG laser and a laser interferometer. The wave components of bulk waves and surface waves (cylindrical Rayleigh waves and WG modes) are analyzed by comparing the numerical and experimental waveforms. The results are in good agreement.
利用激光超声技术从理论和实验两方面研究了弹性圆柱体内声波的激发与传播。给出了脉冲激光线源冲击弹性圆柱母线所激发的二维声场的理论分析。详细分析了圆柱瑞利波和高阶模式——回音壁（WG）模式的色散特性。计算了位于圆柱直径与源相对的另一端的检测点的数值瞬态位移波形。在主要由调Q Nd:YAG激光器和激光干涉仪组成的激光超声系统上对铝圆柱体内的声波进行了实验激发和检测。通过比较数值和实验波形，分析了体波和表面波（圆柱瑞利波和WG模式）的波分量。结果吻合良好。
