中文摘要：

长距离管道超声导波检测技术是一种新的管道无损检测技术，可以时常规方法无法接近的管道进行快速检测，工程应用前景非常广阔．本文对管道超声导波检测过程中传感器的数量和布置间距对输出导波信号的影响进行了讨论，并以纵向轴对称导波L（0，2）为例，就导波模态及频率的选择对检测效果及一次性检测长度的影响进行了研究-综合多方因素选择的最优试验频率即可作为现场管道试验的检测频率．

英文摘要：

Ultrasonic guided waves technology is introduced as a new non-destructive pipe inspection method for its rapid, long distance inspection and applied to special pipes which are inaccessible to other conventional NDT methods. It enjoys widespread use in the field of long range pipe inspection. The inspection distance, as the traveling range of guided waves one, is dependent on propagation characteristics of ultrasonic guided waves. Influence of transducer type, number and ring spacing on characteristics of excited signals is investigated and ultrasonic guided waves mode selection is discussed. The problem of optimum frequency selection is studied by taking example of longitudinal guided waves mode L（0,2）. The correspondent parameters, such as pipe diameter, thickness and suppression of other waves modes are taken into account. The best experimental frequency result can be used as a reference for site inspection.