Research Of Steel Plate Stress Detecting System Based On The Barkhausen Effect

Ferromagnetic material have been widely applied in various fields like transportation,academic research and daily life,and today’s industrial manufacturing is developping toward high-speed and high-load.The load stress, residual stress and thermal stress will be has an important impact on the ferromagnetic material, it may cause defects even rupture resulting in unnecessary losses. Stress concentration is the main cause of failure of ferromagnetic material strain. With the non-destructive testing technology innovation and development in the early 20 th century, it was discovered that the Barkhausen effect detection technology. Barkhausen effect detection technology has been widely applied in experiments and practice.The presence of ferromagnetic material stress on the structure and motion of magnetic domains of impact. When a ferromagnetic material is magnetized, since ferromagnetic domains dislocation, it will generate Barkhausen signals. In this paper plates for the detection of an object by comparing the effects of different forms of detection coil placed on the Barkhausen signal size, the use of a common excitation coil and detection coil form, the first detection coil is wound evenly on the U-shaped core, fixed with tape after and then the upper uniform in the detection coil wound excitation coil. By further comparison experiment to compare the effects of different excitation frequency of Barkhausen signal size, choose the appropriate excitation frequency magnetic test plate.Further experiments are subject to different types of stress on steel specimens for testing, observation and change the size of Barkhausen signals, analyze trends Barkhausen signal with stress. The results show that: the size of the Barkhausen signal and the stress of a ferromagnetic material has a relatively close relationship, when external force is applied to the ferromagnetic plates so that the internal stress, resulting ferromagnetic magnetic domain structure has changed, thus It led to changes in Barkhausen signals. Experimental results show that at low frequencies, Barkhausen signal is stronger than the obvious, when the external magnetic field direction parallel to the direction of the force, with increasing tensile stress suffered ferromagnetic material increases. Thus, the detection of steel stresses can be achieved by detecting the Barkhausen signal.