Design and experimental research of stress measurement system for ferromagnetic components based on ACSM method

Stress is one of the important factors that cause fatigue and fracture of ferromagnetic components, and its accurate measurement is of great significance to ensure the safety and reliability of components. Accordingly, a set of alternating magnetic field stress measurement system was designed and developed. The system includes a measurement sensor, DDS signal excitation module, signal conditioning module, signal acquisition, and processing module. The system was used to carry out uniaxial tensile testing of Q235 steel, and the influence of different testing parameters on the testing signal was studied. The research results show that: in the elastic stage, there is a good linear relationship between the real part of the detection signal and the tensile stress. This characteristic quantity can be used to evaluate the stress of ferromagnetic materials; In addition, the correlation coefficient and sensitivity of different detection parameters were compared through linear fitting analysis, and a set of best detection parameters were obtained. Under this parameter, the correlation coefficient reaches 0.991, and the sensitivity is 7.318 mV/kN. The above research provides test methods and techniques for ferromagnetic material stress measurement.