抄録
Ultrasonic guided wave has a great potential in rapid long-range nondestructive evaluation for pipeworks. However, the wave motion in a pipe is very complex due to the multi-mode existence and dispersivity. Especially in a curved region of a pipe called elbow, there is no theoretical solution like the normal mode expansion in a straight pipe. A semi-analytical finite element technique is one of the most efficient techniques for calculations of guided wave propagation in a pipe because it does not require discretization in the longitudinal direction. In this study, the semi-analytical finite element method gives dispersion curves and wave structures for each guided wave mode. Then, wave propagations in a straight pipe and in a pipe with an elbow are shown. Moreover, experimental results show the potential of longrange pipe diagnostics with the low frequency and non-dispersive region of L(0,2).
