抄録
In recent years, guided wave gathers attention as means of nondestructive inspection of wire ropes. In this paper, we investigate propagation configurations of guided waves generated by Electromagnetic Acoustic Transducers (EMATs) by analysis, numerical calculation and experiments. From results of magnetic field numerical analysis, we found that the Lorentz force and the magnetic flux density generated by EMATs distribute over surface element wires of peripheral strands near EMAT's coils. From experimental results of arrival times of received signals, we calculated the propagation velocity of guided waves. The velocity shows that guided waves are mainly propagated as Longitudinal(0,1)-mode (L(0,1)-mode). Thus, we conclude that guided waves are propagated through each element wire of a peripheral strand near EMAT's coils mainly as L(0,1)-mode.
