超磁致伸缩材料内部磁场与涡流损耗理论分析

在对纵向激励磁场中超磁致伸缩材料进行分析的基础上,利用Maxwell's方程建立了用Bessel函数描述的超磁致伸缩材料内部磁场分布函数,由Bessel函数解析方法确立了超磁致伸缩材料内部磁场Kelvin表达式.通过对材料内部磁场分布的定性分析,得出内部磁场具有典型滞回特性.利用磁能理论对材料内部涡流损耗进行了初步理论分析,得出由Kelvin函数表示的材料内部涡流损耗表达式.并对激励频率、电导率、材料半径等因素对涡流损耗的影响进行了初步讨论,为超磁致伸缩材料参数的选取奠定了基础.

Theoretical Analysis of Magnetic Field and Eddy Current Loss Within Giant Magnetostrictive Material

Discussing the giant magnetostrictive material in the longitudinal exciting magnetic field and introducing the Maxwell's equation to obtain the magnetic field distribution function in terms of Bessel function within the giant magnetostrictive material,the Kelvin expression of magnetic field in giant magnetostrictive material is given by the analytical method from Bessel function.A qualitative analysis is made to the magnetic field distribution to reveal the classical hysteresis characteristic of internal magnetic field.Based on the theory of magnetic energy,the eddy current loss within material is preliminarily discussed to get the expression of eddy current loss within material in terms of Kelvin function.Then,the effect of the influencing factors on eddy current loss are also discussed,such as exciting frequency,electrical conductivity and radius of giant magnetostrictive material,thus laying down a foundation on which the selection of proper parameters for giant magnetostrictive material parameters is available.