摘要
通过管道超声导波缺陷反射理论和检测理论,分析了超声导波与缺陷作用后的传播特性。为了对管道中缺陷信号进行辨识,利用周向压电晶片阵列在带有不同缺陷的管道中激励不同频率的L(0,2)模态导波对管道进行缺陷检测实验,研究了导波激励频率、模态转换后各模态幅值与缺陷尺寸的关系。结果表明,在缺陷截面比与信号激励频率相同的情况下,裂纹缺陷的反射系数比腐蚀缺陷的反射系数大;L(0,2)模态导波与裂纹缺陷相互作用后会产生F(2,3)模态;与缺陷同一周向位置的压电片接收的反射回波幅值最大。
Interaction of defects with ultrasonic guided waves in pipelines has been analyzed under the defect reflec- tion and detection theories of ultrasonic guided waves. To identify defects in pipelines, with the application of cir- cumferential piezoelectric transducer array, L （0,2） mode in different frequencies has been excited to investigate the relationship between excitation frequencies, amplitudes of converted modes and defect sizes. Results show that with the same excitation frequency, reflection coefficient of crack is larger than that of corrosion when their defect cross-section areas are equivalent; F（2,3） mode was found when L（0,2） is interacted with cracks; the piezoelec- tric transducer sharing the same circumferential position with defects can receive highest reflection signal. The result in this paper is important for the identification of defects in pipelines by using ultrasonic guided waves.
出处
《机械科学与技术》
CSCD
北大核心
2014年第4期551-554,共4页
Mechanical Science and Technology for Aerospace Engineering
基金
江苏省特检院2012年度科技项目(KJ(Y)2012049)资助
关键词
超声导波
模态转换
信号辨识
管道检测
corrosion
defects
fatigue crack propagation
inspection
mode conversion
piezoelectric transducers
pipe inspection
pipelines
reflection
schematic diagrams
signal identification
ultra- sonic equipment waveguides
ultrasonic guided waves
velocity
