Study of magnetoelastic demagnetization of locally magnetized steel

Abstract

To improve the accuracy of determining mechanical stresses in steel by the method of magnetoelastic demagnetization (magnetoelastic memory), the magnetoelastic sensitivity of the material to elastic stresses is additionally measured by applying or removing an additional load of a known value. We present the results of studying the magnetoelastic demagnetization of locally magnetized steel by varying stresses of the uniaxial tension or compression against a background of the base load. The magnetoelastic sensitivity of the steel in a loaded state to variable stresses has been assessed. It is shown that the determination of the magnetoelastic sensitivity of the steel to variable loads makes it possible to improve the accuracy of estimating base stresses in the steel structure using magnetoelastic methods. It is revealed that a decrease in the strength of the magnetic scattering field of the local residual magnetization (LRM) of the steel after variable loading (or unloading) exponentially depends on the magnitude of the base stresses. The possibility of controlling the uniaxial mechanical stresses in steel structures in the magnetoelastic memory mode which is based on the dependence of the strength of magnetic scattering field of the local residual magnetization of the steel on the uniaxial stresses is shown. A method for monitoring uniaxial stresses in the elements of steel structures by the method of magnetoelastic memory is proposed using the measured magnetoelastic sensitivity of the material. The results obtained can be used in the development of a method for monitoring the stress-strain state of steel structures during operation under the simultaneous effect of static and dynamic loads.