The transmitter generates guided wave in the plate according to magnetostrictive effect,and then it propagates in the plate and is reflected by the damages and edges of the plate.

• 根据反射信号的到达时间和波在板中传播的速度,可判断出板中缺陷所在位置。改变恒定偏置磁场与时变磁场的方向可以在板中激励不同波型的导波。