Metal Magnetic Memory Testing Device Based On Gradient

Metal magnetic memory testing technology has an important meaning on preventing fatiguedamage caused by the accident.Because the testing can find out the stress concentration in conponentrapidly,assess the safety of equipment accurately without pre-processing and excitation magneticfield.Thus metal magnetic memory testing technology has attracted many domestic scholars’ attentionin recent years.This paper firstly discusses the present situation and development application of the metalmagnetic memory testing research, study deeply on the theoretical basis of magnetic memory testing.According to the study, material mechanics ferromagnetic, on the stress concentration the magneticfields produced by the mathematical modeling. It also analyzes the influence of external environmenton magnetic memory testing.Secondly, according to the principle of magnetic memory testing, we analysis vertical gradient asthe feasibility of metal magnetic memory testing, and conclude that the vertical gradient value ofmagnetic field is more obvious stress concentration of value.Thirdly, according to the basic principles of the gradient method magnetic memory testing, theuse of piezoelectric bimorph vibration to achieve magnetic field gradient of the collection, developedthe magnetic field gradient value based on vibration testing instruments. Through the increased testingchannel and on the hardware and software of the transformation, and realize the gradient testinginstrument in rail stress concentration and the application of the defects detection.Finally, by using magnetic field gradient detector, unifiing the related theory, detect the magneticfields of A3steel bar when tensile testing, we got the conclusion: The magnetic field gradient isinversely proportional to the fourth of the lift-off hight; The demagnetization caused by time effectwill weaken the gradient value of magnetic field; When the bar has prduced necking, the magneticfield gradient value developing severe bigger phenomenon conclusion.