基于主动磁化的钢板应力测量性能提升方法研究

提出一种提高基于磁弹效应的钢板应力测量灵敏度和一致性的方法。从力磁耦合理论模型出发，分析强磁化和弱交流磁化对力磁耦合所起的作用：强磁化能通过降低初始磁导率和统一力磁耦合参数，提高应力测量的灵敏度及一致性；弱交流磁化提供小幅振荡磁场，能有效消除干扰磁场影响。开展了基于磁弹法的钢板应力测量有限元仿真研究，表明当初始相对磁导率较低时，应力作用下的钢板法向磁感应强度变化率较大，即应力测量灵敏度较高。开展了不同强磁化条件下不同厚度钢板的拉伸试验，测量其法向磁感应强度变化。实验结果表明：与未磁化相比，强磁化后钢板应力测量灵敏度有数十倍提升，一致性有数倍至百倍提高。其中，3 mm厚度钢板采用单磁铁移动磁化方式的应力测量灵敏度和一致性参数提高至1.665 mGs/MPa和2%;5 mm厚度钢板采用双磁移动磁化方式的应力测量灵敏度提高至1.41 mGs/MPa,采用单磁铁移动磁化方式的一致性参数提高至0.2%;7 mm厚度钢板采用双磁铁移动磁化方式的应力测量灵敏度和一致性参数提高至1.2 mGs/MPa和1.8%。

Research on improving the performance of steel plate stress measurement based on active magnetization

Proposes a method to improve the sensitivity and consistency of stress measurement for steel plates based on magnetoelastic effects. From the framework of the theoretical model of magnetoelastic, it analyzes the roles of strong magnetization and weak AC magnetization:Strong magnetization can improve the sensitivity and consistency of stress measurement by reducing the initial magnetic permeability and unifying the parameters of the magnetoelastic model. Weak AC magnetization provides a minor oscillating magnetic field, which can effectively eliminate the influence of interfering magnetic fields. A finite element simulation study on stress measurement of steel plates based on the magnetoelastic method is conducted, and the results demonstrate that when the initial relative permeability is low, the change rate of normal magnetic induction intensity of the steel plate under stress is relatively high, which indicates a high sensitivity of stress measurement. Tensile experiments are conducted on steel plates with different thicknesses under different strong magnetization conditions to measure the changes in normal magnetic induction intensity. The experimental results show that compared with unmagnetized case, the sensitivity of stress magnetic measurement has been improved by strong magnetization by tens of times, and the consistency has been improved by several to hundreds of times. The stress measurement sensitivity and consistency parameter of 3mm thick steel plates using single magnet moving magnetization method have been improved to 1. 665 mGs/ MPa and 2% . The sensitivity of 5 mm thick steel plates using dual magnets moving magnetization method has been enhanced to 1. 41 mGs/ MPa, and the consistency parameter of 5 mm thick steel plates using single magnetic moving magnetization method has been increased to 0. 2%. The sensitivity and consistency parameter of 7 mm thick steel plates using dual magnets moving magnetization method have been improved to 1. 2 mG/ s/ MPa and 1. 8%.