Research on Working Clearance Optimization for Non-contact Stress Detection with Magneto-elastic Stress Sensor

In order to acquire the optimal working clearance for non-contact detecting stress of steel members with magneto-elastic stress sensor, a magneto-elastic sensor probe with E-shaped structure is adopted for carrying out the relevant research. Firstly, the principle of non-contact stress detection is discussed based on magneto-elastic effect, and the magnetic circuit of the magneto-elastic stress sensor is analyzed for deducing the basic output voltage equation of sensor when tested pieces(low carbon steel Q235) is loaded with uniaxial stress, on the basis of ferromagnetism and presented references, the technical parameter of sensor is determined for designing non-contact stress detection system. After that, focusing on the design of the testing program with different excitation frequencies and air gap, actual experiments are carried out to optimize working clearance when tested pieces are loaded with uniaxial stress. Results of the test show that this kind of sensor is not only simple in structure but also valuable with non-destructive, convenient and fast measurement of stress in application.