基于热弹激发机制，建立了激光在圆柱侧面激发超声波的有限元模型，研究了在不同厚度及不同曲率半径下铝质圆柱(管)中头波的传播规律，分析了头波的传播特性。模拟结果表明：头波在柱体内部一定角度范围(临界角)内产生，并以略大于瑞利波的速度沿直线传播，在传播过程中逐渐远离瑞利波，并向纵波逼近；临界角(最大振幅处)的正弦值近似等于柱体中瑞利波与纵波的波速之比；在界面处，一部分头波渗透出来沿周向传播，并迅速衰减，另一部分则发生反射，沿直线传播至界面处渗出，没有发生明显的衰减。

A method based on thermo-elastic excitation of ultrasonic waves generated by laser at the surface of a cylinder is presented. The propagation rules of head waves at the aluminum cylinders with different radii or different thicknesses are researched. The propagation characteristics of head waves are analyzed. The numerical results show that head waves are generated at the certain range (critical angle) in the body, and then spread along the straight line at a speed slightly larger than that of the Rayleigh waves. In the propagation process, the head waves move away from the Rayleigh waves and approximate longitudinal waves. The sine values of the critical angle (at the maximum amplitude) are almost equal to the wave-velocity ratios of the Rayleigh wave and longitudinal-wave in the cylinder. At the interface, a part of the head wave escapes from the body and spreads along the circumference with a rapid attenuation, while the other part of the head wave has a reflection at the interface with a small attenuation.