电磁颗粒阻尼器模型及铁磁颗粒力学特性研究

Discrete element method model of electromagnetic particle damper and mechanical properties of ferromagnetic particles

通过安培环路定理得到了电磁环境下颗粒阻尼器腔体内部的磁场分布,推导并获取了磁化的铁磁性颗粒内部磁场强度与外加磁场之间的关系。在此基础上,将磁化颗粒看作磁偶极子,对电磁场作用下铁磁性颗粒之间的受力特性进行了分析,并通过有限元法对颗粒之间的受力进行了验证。研究结果表明:电磁颗粒阻尼器(EPD)内颗粒所受磁力主要是磁化颗粒之间的相互作用,颗粒所受磁力与颗粒间的距离,以及颗粒之间距离向量与磁场的空间位置关系有关;距离越远,磁力越小。当两颗粒相对位置与磁场方向一致时,颗粒之间表现为吸引力;而当两颗粒相对位置与磁场方向垂直时,表现为排斥力。最后,结合离散元法,建立了电磁颗粒阻尼器的离散元模型,并通过实验对比了电磁颗粒阻尼器腔体内的颗粒分布,验证了模型的有效性。为电磁场下颗粒阻尼器阻尼耗能特性的研究奠定了理论基础。

In this paper, the distribution of the magnetic field in an electromagnetic particle damper(EPD) is analyzed based on the Ampere’s circulation theorem, and the relationship of the magnetization between the ferromagnetic particle and the intensity of the applied magnetic field is derived. Moreover, the magnetized particle is considered as a magnetic dipole, and the magnetic force between particles is studied, and which is verified by the finite element method. It is shown that the magnetic force of the particle is mainly caused by other magnetized particles, which is affected by the distance between two particles and angle between the direction of the magnetic field and the position vector of the two particles. The larger the distance is, the smaller the magnetic force will be. The magnetic force is attraction when the position vector of the two particles is parallel to the magnetic field, and which is repulsion when the position vector is perpendicular to the magnetic field. Finally, the discrete element method(DEM) model of EPD is established, which is verified by comparing the distribution of the magnetizedparticles in the EPD to the experiment. Results obtained may provide a beneficial reference for the damping performance researches of EPDs.