Stress Measurement Technology And Research Of Ferromagnetic Material Based On Coercive Force

The ferromagnetic material has good mechanical properties,which is the most prevalent material using in the petroleum industry.The ferromagnetic material component is always affected by various kinds of stress during the working process.Whenever the stress concentration reaches a kind of degree,the component would have partial deformation,which leads the component no longer worked or lead the safety accidents.Therefore,stress measurement or called detection is an urgent problem now.In this paper,we focus on a kind of stress measurement system of ferromagnetic materials based on coercive force,utilizing electromagnetic detection technology to collect the data of the tested stress of hysteresis loops and then calculate the coercive force and remanence parameters in order to complete the early safety assessment of ferromagnetic materials.Firstly the paper introduces the normal stress measurement methods of the ferromagnetic material and the basic theory of coercive force measurement of ferromagnetic material in this research,and a coercivity-based ferromagnetic material stress detection method based on a controllable periodic magnetic field is proposed.The method forms a controllable periodic magnetic field through a DDS signal generating device and a cascaded power amplifying device.We complete the magnetization of the ferromagnetic material under low frequency,and then get synchronous acquisition of magnetic field excitation signal and induced magnetic field signal by a dual synchronous coercive force receiving device which reduced the error of drawing hysteresis loops between excitation and inductive signals.Through the design of the coercive force stress comprehensive analysis software to calculate the magnetic field excitation signal and induced magnetic field signal to complete the extraction of the two characteristic data of coercive force and residual magnetism,and cubic B-sample curve fitting method to optimize the AD collection data and obtain the complete hysteresis loop.Finally,the developed coercivity-based ferromagnetic material stress measurement system was tested in a laboratory environment and the outside.It shows that the coercive force value increases while the pulling force is increasing,and the remanence magnetism changes timely with the increase of the pulling force.The coercive force and remanence can be used to analyze the ferromagnetic material,which verifies the feasibility of the system.Effectiveness is of great significance for the detection of safety performance of iron magnetic materials and prevention of safety accidents.