Experimental analysis on the influence of freeform bending on Barkhausen noise for steel tubes

Freeform bending with a movable die makes it possible to bend complex structures and seamless radii without changing the bending tools. Currently, most research focuses on minimizing the geometrical deviations without considering the mechanical properties of the bent tubes. A previous work showed, that the geometry can be decoupled from the mechanical properties with non-tangential bending [1]. The implementation of a soft sensor based on ultrasonic contact impedance measurements (UCI) of the property-controlled freeform bending has also been examined [2], as well as a structure for closed-loop control based on material properties [3]. The present work deals with a micro-magnetic sensor and Barkhausen noise (BHN) and investigates its suitability for the closed-loop control. For this purpose, different processing routes for freeform-bent steel tubes are experimentally investigated by their characteristic BHN. In addition to an existing simulation model, a data basis for the impact of freeform bending parameters is built to extend the existing model of a property-based closed-loop control