超高场脉冲磁体失效及结构屈曲研究  

Study on Failure and Structural Buckling of Ultra-High Field Pulsed Magnets

作　　者：肖后秀 黄煜 Xiao Houxiu;Huang Yu(Wuhan National High Magnetic Field Center Huazhong University of Science and Technology,Wuhan 430074 China;School of Electrical and Electronic Engineering Huazhong University of Science and Technology,Wuhan 430074 China)

机构地区：[1]华中科技大学国家脉冲强磁场科学中心,武汉430074 [2]华中科技大学电气与电子工程学院,武汉430074

出　　处：《电工技术学报》2022年第19期5067-5073,共7页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划(2021YFA1600303);湖北省重点研发计划(2021BAA167)资助项目。

摘　　要：结构力学表明,磁体失效包含材料强度失效和结构整体失效两个方面。现有磁体失效模型是基于材料强度模型,忽略结构失稳问题,难以解释超高场脉冲磁体经常在低于其设计值就发生破坏的现象。且已有研究显示,屈曲是导致超高场脉冲磁体失效的主要原因之一,但脉冲磁体屈曲的形成机理和演变规律尚不明确。该文从结构稳定性的角度出发,分析指出脉冲磁体自由分离层可等效为薄壁圆柱壳,具有高屈曲风险,并提出基于圆柱壳体结构屈曲的超高场脉冲磁体力学失效分析方法,建立脉冲磁体静态电磁屈曲Ansys有限元模型,进行了屈曲行为研究分析,仿真结果与实际结果吻合。屈曲分析结果表明:在电磁载荷方面,轴向电磁力是产生屈曲的决定性因素,径向电磁力对于外层绕组轴向屈曲的影响不明显,可在一定程度上抑制内层绕组的轴向屈曲;在绕组结构方面,外层绕组对螺旋绕组缝隙较为敏感,需重点关注。The theory of structural mechanics shows that magnet failure can be attributed to overstress failure or windings buckling. The present magnet failure model is based on the stress model and ignores the problem of structural instability, which makes it impossible to explain why ultra-high fieldmagnets frequently sustain damage at low stress levels. However, the mechanism and criterion of buckling in pulsed magnets are still unclear. Previous study has indicated that buckling is another significant cause of ultra-high field pulsed magnet failure. In this paper, the free-standing layer of the pulsed magnet can be equivalent to a thin-walled cylindrical shell with a high risk of buckling. A failure analysis method of ultra-high-field pulsed magnets based on the buckling of the cylindrical shell structure, along with an Ansys finite element model of the static electromagnetic buckling, is proposed.The simulation results match well with the experimental results. The buckling analysis shows that: the axial electromagnetic force is the key factor for buckling, while the radial electromagnetic force has no significant effect on the axial buckling of the outer winding, and itcan suppress the axial buckling of the inner winding to some extent;in terms of winding structure, the outer winding is more sensitive to the spiral winding gap and needs to be focused on.

关 键 词：脉冲强磁场 脉冲磁体 自由分离层 屈曲 

分 类 号：TM551[电气工程—电器] O342[理学—固体力学]