超磁致伸缩作动器的结构分析

从力学和磁学两方面分析了超磁致伸缩作动器内部结构形式对作动器特性的影响,重点研究了永磁铁式偏置磁场的不同结构形式以及作动器外壳材料对作动器的输出性能及作动器轴向刚度的影响.研究结果表明,环套式永磁铁的结构形式不可避免地在作动器外围产生较大磁场;分段式永磁铁的结构形式,采用钢制外壳时可避免漏磁;但是在芯棒区域的磁场与理想均匀磁场的差异将给作动器的输出位移带来较大损失,对作动器的刚度也会产生不可忽略的影响,二者在设计中必须考虑.在结构分析的同时,基于超磁致伸缩材料的特性提出了磁场与刚度相关联的设计理念,可为超磁致伸缩作动器的结构设计提供参考.

Structural analysis of giant magnetostrictive actuator

The structure form of giant magnetostrictive actuator(GMA) was studied in both mechanics and magnetics to obtain the properties of GMA. The patterns of permanent magnet (to induce the bias-magnetic-field), materials of the actuator-s covering and their impact on stroke and stiffness of the GMA were studied. The results show that the ring-type magnet leads to magnetic flux leakage, while the segment-type magnet with the steel covering can eliminate this phenomenon. Meanwhile the difference between the ideal and the actual bias magnetic field around the mandrel would greatly reduce the GMA-s stroke and has an assignable effect on the GMA-s stiffness. Both the stroke and the stiffness of the GMA must be considered in design. A novel design concept of the coupling magnetism and stiffness based on the properties of magnetostrictive material was proposed. The concept can provide a reference for structural design of GMA.