Non-contact Longitudinal Modal Testing of a Non-ferromagnetic Pipe Using Magnetostrictive Patches

자기 변형 패치를 이용한 비자성 배관의 비접촉 종진동 모달 테스팅

Non-contact modal testing for longitudinal modes of a pipe is discussed in this work. The suggested method can generate and measure longitudinal vibrations without mechanical contact by using the coupling phenomenon between deformation and magnetic field, known as the magnetostrictive effect. This effect has been used to generate and measure ultrasonic waves, but seldom used to deal with audible vibrations. In this investigation, the validity of the developed method in a typical vibration frequency range is checked with an inconel pipe being used in nuclear power plants.