弯管中超声导波传播特性的研究  

Research on the Propagation Characteristics of Utrasonic Guided Waves in Curved Pippes

作　　者：王秀彦[1] 刘增华[1] 孙雅欣[1] 何存富[1] 吴斌[1] 

机构地区：[1]北京工业大学机械工程与应用电子技术学院,北京100022

出　　处：《北京工业大学学报》2006年第9期773-777,共5页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(10272007;10372009);北京市自然科学基金资助项目(3011001).

摘　　要：为了利用超声导波检测弯管中的缺陷,研究了L(0,2)模态在弯管中的传播特性．通过实验得到了不同曲率半径的90°弯管中L(0,2)模态的透射系数．结果表明,L(0,2)模态在弯管中传播时会出现模态转换现象,幅度有相应的衰减,从而影响导波的传播距离和缺陷检测能力;随着曲率半径的增大,L(0,2)模态的透射系数逐渐越小,并且对于同一弯管,激励频率越大,透射系数也越小．The propagation characteristics of L （0, 2） mode in curved pipes are investigated theoretically and experimentally for the purpose of defect detection in curved pipes by using ultrasonic guided wave. With experiments, transmission coefficients of L （0, 2） mode in 90° curved pipes with different curvature radii are tested. Results show that mode conversion phenomena happen and their amplitude attenuates consequently when L （0, 2） mode propagates in curved pipes, and propagation distance and capability of defect detection are effected. Furthermore, transmission coefficients of L （0, 2） mode decrease while curvature radii increase. When excitation frequencies increase in the same curved pipe, transmission coefficients decrease.

关 键 词：导波 透射系数 弯管 模态 

分 类 号：TB559[理学—物理]