Patent ID: 7621189

Claim:
An apparatus for generating and sensing torsional vibrations using magnetostriction, the apparatus comprising a torsional vibration generating part transmitting torsional vibrations to a test part having an arbitrary cross-section and a predetermined length, and a torsional vibration sensing part sensing the torsional vibrations generated from the torsional vibration generating part, wherein the torsional vibration generating part and/or the torsional vibration sensing part comprises: a magnetostrictive body that is attached around the test part and is made of a magnetostriction material; a first magnetic field forming part forming a magnetic field in a circumferential direction of the test part along with the magnetostrictive body; and a second magnetic field forming part forming a magnetic field around the magnetostrictive body in a direction substantially perpendicular to the direction of the magnetic field formed by the first magnetic field forming part and in parallel with a longitudinal direction of the test part, wherein the magnetostrictive body is segmented into a predetermined number of magnetostrictive pieces in a circumferential direction of the test part, wherein the magnetostrictive pieces are substantially the same size and attached around the test part at substantially equal intervals from each other in a circumferential direction of the test part.