强冲击载荷下电磁缓冲器有限元仿真模型

Finite Element Simulation Model for Electromagnetic Buffer under Intensive Impact Load

为获得强冲击载荷下电磁缓冲器的电磁与阻尼特性,针对其速度高、加速度大的运动特点,提出了一种改进的指数去磁模型来模拟钕铁硼永磁材料的去磁过程,同时采用一种改进的矢量磁滞模型来考虑软磁材料的磁滞效应。在此基础上,建立考虑去磁效应与磁滞效应的初级-次级涡流耦合时步有限元模型。采用冲击载荷模拟实验,验证了有限元模型的准确性;结合磁场测试得到并分析了冲击电磁缓冲过程的电磁与阻尼规律;通过开展强冲击载荷实验得到了电磁缓冲器高速运动条件下的阻尼规律。研究结果表明:数值分析方法具有高可靠性;去磁效应随缓冲速度增大而增强;阻尼系数随着缓冲速度的增大而减小;磁滞作用能扰乱磁场分布,影响阻尼力变化规律。

In order to obtain the electromagnetic and damping characteristics of the electromagnetic buffer under intensive impact load,an improved exponential demagnetization model is proposed to simulate the demagnetization process of NdFeB permanent magnets.An improved vector hysteresis model is adopted to consider the hysteresis effect of soft magnetic materials.And a primary-secondary eddy current coupled time-step finite element model is established,in which demagnetization and hysteresis are considered.The accuracy of the finite element model is verified through the laboratory impact load test.The damping and electromagnetic characteristics were obtained and analyzed through the magnetic field test.The intensive impact test was carried out to obtain the damping characteristics of electromagnetic buffer under high buffering velocity conditions.The results show that the finite element model has high reliability.The demagnetization effect increases with the increase in buffering velocity,which leads to the decreased damping coefficient.Hysteresis effect can disturb the magnetic field distribution and affect the damping force.