Defect and Tension Detection of Magnetostrictive Longitudinal Guided Wave for Steel Strip

The traction technology used in elevators has gradually changed from wire ropes to steel strips, which are composed of rubber and multiple steel wire ropes. Traditional detection methods can only detect defects in the rubber surface but not in the internal wire ropes. At present, there is no effective way to realize nondestructive testing of steel strips. Therefore, a magnetostrictive longitudinal guided wave sensor is designed in this paper for the nondestructive testing of elevator steel strips. The design of the sensor is determined by comparing different longitudinal guided wave sensor structures through simulation. Changes in the natural frequencies of a steel strip are used to monitor changes in its tension. Finally, the proposed sensor is verified to be able to detect defects in steel strips.