Irreversible demagnetization mechanism of permanent magnets during electromagnetic buffering  

作　　者：Zi-xuan Li Guo-lai Yang Yu-meng Fan Jia-hao Li 

机构地区：[1]School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing,PR China

出　　处：《Defence Technology（防务技术）》2021年第3期763-774,共12页Defence Technology

基　　金：primarily supported by the National Natural Science Foundation of China(grant number 301070603)。

摘　　要：The permanent magnets will be irreversibly demagnetized under high temperature and high velocity during the electromagnetic buffering.In this study,the magnetic field induced by eddy currents and the self-demagnetizing field of permanent magnet are taken into consideration together for demagnetization analyse.The magnetic Reynolds number is used to express the eddy currents demagnetization.The correction coefficient being expressed as the index of the air-gap width,the inner cylinder thickness,iron pole axial length and the permanent magnet demagnetization coefficient is introduced by magnetic path analysis to represent the self-demagnetization effect and the demagnetization extent.The electromagnetic buffer(EMB)prototype is tested under intensive impact loads of different strengths at room temperature.The accuracy of the nonlinear irreversible demagnetization finite element model is verified by demagnetization on damping force,velocity and displacement.Finally,high-velocity demagnetization and high-temperature demagnetization are analysed in order to obtain the distribution law of irreversible demagnetization.

关 键 词：EMB Irreversibly demagnetization Magnetic Reynolds number Correction coefficient 

分 类 号：TJ01[兵器科学与技术—兵器发射理论与技术] TM273[一般工业技术—材料科学与工程]