公开(公告)号：KR1020050098580A

公开(公告)日：2005-10-12

申请号：KR1020040023851

申请日：2004-04-07

Applicant: 재단법인서울대학교산학협력재단

Inventor： 한순우 ,  박찬일 ,  김윤영

IPC: G01H11/02

CPC classification number: G10K9/128 ,  G01H13/00 ,  G01H11/02

Abstract: An apparatus for generating and measuring bending vibration in a pipe buried underground or a pipe covered by insulating materials is disclosed. There is provided an apparatus for generating and measuring bending vibration in a non-ferromagnetic pipe without physical contact, comprising: a ferromagnetic strip adhered on a surface of the pipe; a coil wound around the surface of the pipe; two magnets for generating bias magnetic field, applied to the strip and parallel to the strip; a power source for supplying an electric current to the coil; and a measuring unit for measuring variation of voltage across the coil, the variation of the voltage being generated due to a strain according to inverse magnetostrictive effect, the strain being generated due to bending vibration, the bending vibration being generated due to deformation of the strip, the deformation being induced according to magnetostrictive effect as the power source supplies the electric current to the coil.

公开(公告)号：KR1020050081574A

公开(公告)日：2005-08-19

申请号：KR1020040009887

申请日：2004-02-16

Applicant: 재단법인서울대학교산학협력재단

Inventor： 박찬일 ,  조승현 ,  한순우 ,  김윤영

IPC: G01N27/82

CPC classification number: G01N27/82 ,  B06B1/08 ,  G01N11/162 ,  G01N2291/0426 ,  G01R33/3873

Abstract: A method and an apparatus for structural diagnosis, which generates torsional waves upon a shaft, beam or pipe having arbitrary cross-sections, such as a circular cross-section, and senses existence or location of the cracks through analyzing reflected waves are disclosed. A magnetostrictive transducer comprises a plurality of ferromagnetic strips attached around a circumference of a member having a arbitrary cross-section with a fixed inclination; a first housing disposed to surround the ferromagnetic strips, the first housing being made of insulating material; and a coil would around the first housing. The magnetostrictive transducer can generate torsional waves upon a member when a current is supplied to the coil, and can measure reflected torsional waves.