摘要
理论分析了管中L(0,2)模态导波的激发特性,将在不同圆周位置接收的缺陷反射声场分解为L(M,2)模态簇,通过数值频散补偿方法实现所分解信号的时间-空间变换,并用变换后的信号实现管中导波缺陷成像。采用有限元仿真研究了激励源的选择对管中周向导波的抑制作用,以指导实际检测中激励换能器阵列阵元分布。实验研究了实现该成像方法的激励和接收压电晶片的配置,并对含单、双槽型裂纹缺陷的管道进行成像,验证了该方法的有效性。结果表明,该方法可实现管中裂纹缺陷的轴向及周向定位,为实现管道健康状况监测打下基础。
Generation characteristics of L（0,2） mode are theoretically studied, the reflected acoustic field is recorded on different circumferential positions and decomposed into a L（M,2） modal cluster, numerical dispersion compensation technique has been employed to implement a time-space transform of the decomposed signals, and the defect imaging is achieved with the transformed signals. In order to restrain circumferential guided waves, the selection of exciting sources is studied by FE and the results are used to set the distribution of elements in a transducer array. The configuration method of exciting and receiving piezoelectric wafers is studied to achieve the imaging algorithm. The validation of the algorithm is experimentally verified using pipes through thickness cracks and dual-defects. The results show that the method can locate the axial and circumferential position of cracks and can be used as the technical foundation of pipe health monitoring.
出处
《工程力学》
EI
CSCD
北大核心
2013年第6期288-294,300,共8页
Engineering Mechanics
基金
国家自然科学基金项目(10772009)
