OPEN MAGNETIC CIRCUIT-BASED METHOD AND DEVICE FOR DETECTING MAGNETOSTRICTIVE GUIDED-WAVE

摘要

Provided is an open magnetic circuit-based sensor for detecting a magnetostrictive guided-wave. The sensor comprises: an excitation coil (7); a receiving coil (8); and a magnetic device. The magnetic device comprises multiple detection modules arranged evenly in a circumferential direction and configured to be attracted to an outer side of a test elongated member (9). Each detection module comprises: a housing; a permanent magnet (5); and a magnetic inductive board (6). Every two adjacent housings are connected via an adjustment device. The excitation coil (7) and the receiving coil (8) are close to the detection modules and are disposed together with an axle bush at the outer side of the test elongated member (9). A sinusoidal alternating current is inputted to the excitation coil (7) to generate an induced voltage in the receiving coil (8), and a computer (10) is caused to receive the induced voltage and determine whether a defect exists in an interior of the test elongated member (9). The sensor is compact, has a simple structure and a light weight, and can be installed conveniently. By connecting coils in series or arranging multiple layers of coils, an amplitude of a detection signal can be enlarged, thereby increasing detection sensitivity.