Dynamics of Structures with Electromagnetomechanical Coupling in Micro-Domain

本文研究了微域内电磁-机械耦合结构的动力学问题。对磁粘滞阻尼和磁刚度效应等现象进行了实验研究。针对微机械中可能出现的磁粘滞阻尼效应，建立了一种数值模拟方法。（1）测量了平板和圆柱在强磁场中的动态响应。采用非感应式应变计和激光多普勒传感器，可以在不受强场影响的情况下测量弯曲应变和侧向位移。通过测量，已经澄清了以下内容。（a）磁粘滞阻尼效应发生在非铁磁和铁磁板中，也发生在非铁磁圆柱体中。（B）在铁磁板中发生磁刚度效应。（2）发展了模态磁阻尼法。并将其应用于非铁磁平板实验。数值计算结果与实验结果吻合较好，验证了该方法的有效性。磁粘滞阻尼比与磁感应强度、杨氏模量、密度、厚度和电导率之间的关系。该方法可以预测微区的磁粘滞阻尼效应。

The dynamics of structures with electromagnetomechanical coupling in micro-domain have been studied in this research. The phenomena, such as magnetic viscous damping and magnetic stiffness effects, have been experimentally investigated. The numerical simulation method to evaluate magnetic viscous damping effect, which may occur in micro-machine, has been developed.The results of this research are summarized as follows.(1)Dynamic responses of plates and a cylinder were measured in strong magnetic field. By using no-induced type strain gages and a laser doppler sensor bending strain and lateral displacement can be measured without the effect of the strong field. From the measurement the followings have been clarified.(a)magnetic viscous damping effect occurs in non-ferromagnetic and ferromagnetic plates, and also in a non-ferromagnetic cylinder.(b)magnetic stiffness effect occurs in a ferromagnetic plate.(2)Modal magnetic damping method has been developed. It was applied to the non-ferromagnetic plate experiment. The numerical results agreed with experimental ones and the validity of the method has been verified. The relation among magnetic viscous damping ratio, magnetic induction, Young's modulus, density, thickness and conductivity. This method enables to predict the magnetic viscous damping effect in micro-domain.