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为指导基于超声导波的管道无损检测,计算并分析水平切变(shear horizontal,SH)导波在具有自由内表面、外表面的弹性各向同性管道周向波导中传播的频散和波结构特性,将这些特性与平板SH导波的对应特性进行对比分析。在周向SH导波的频散特性推导中引入了传播方向弧长的修正算法。研究结果表明,表征管道周向弯曲程度的内半径、外半径之比越大,则管道周向SH导波的频散和波结构特性越接近于平板SH导波的情况,并且较低频率下的平板SH导波的SH0模式和管道周向SH导波的CSH0模式较适合缺陷的检测。
In order to guide the non-destructive testing of pipelines based on guided waves, the frequency and wave structure of shear-horizontal (SH) guided waves propagating in a circumferential waveguide with free internal surfaces and external surfaces is calculated and analyzed. Characteristics, the characteristics of these SH flat-wave guided wave contrast analysis of the corresponding properties. The correction algorithm for the arc length in the propagation direction is introduced in the derivation of dispersion characteristics of the circumferential SH guided wave. The results show that the larger the ratio of the inner radius and the outer radius that characterize the circumferential bending of the pipe, the closer the frequency dispersion and wave structure properties of the SH guided wave in the circumferential direction of the SH plate are and the lower frequency SH SH-mode slab SH-wave guide and the SH-wave direction of the pipe CSH0 mode is more suitable for the detection of defects.