周向超声导波对管道纵向缺陷检测的研究  

Detection of a longitudinal defect in a pipe based on guided circumferential waves techniques

作　　者：李隆涛[1] 何存富[1] 吴斌[1] 

机构地区：[1]北京工业大学机电学院,北京100022

出　　处：《声学学报》2005年第4期343-348,共6页Acta Acustica

基　　金：国家自然科学基金(10272007;19972003)北京市重点基金(3011001)北京市教委科技发展计划资助项目

摘　　要：在弹性动力学理论的基础上,研究了管道中周向超声导波的传播及其频散特性,并数值计算了周向导波的频散曲线。通过所建立的超声导波实验系统,在理论上与实验上研究了斜探头的入射角、频率及周向导波模态的关系,并在外径为88.8 mm、内径为80.8 mm的管道中激励出特定的单一模态周向导波;同时,利用单一模态周向导波对该管道表面上长25 mm、宽1 mm、深0.7 mm的人工缺陷进行了检测。结果表明,同在板中激励单一Lamb波模态类似,选用特定角度的斜探头与特定频率可在管道中激励出单一周向导波模态并有望应用于管道缺陷的检测。Based on elastic mechanics theory, the multi-modes and disperse characteristics of guided circumferential waves in pipe were investigated theoretically and experimentally, the disperse curves of guided circumferential waves were gotten by numerical calculations. The relationships between the angle of beam transducer, frequency and guided circumferential modes were analyzed by our guided wave experiment system. Then single guided circumferential mode was excited in a pipe (O.D 88.8 mm, I.D 80.8 mm). Then an artificial longitudinal defect (25×1×0.7 mm3) on the surface of a pipe was detected by use of the single guided circumferential wave. The results show that single guided circumferential mode can be excited in a pipe by choosing special frequency and special angle beam transducer, as the same as the case of exciting Lamb wave in a plate, and it can be used to find the longitudinal defect on a pipe surface.

关 键 词：周向超声导波 缺陷检测 弹性动力学 频散曲线 

分 类 号：TB551[理学—物理]