考虑非线性电磁分布力的虚拟电动振动系统建模

针对振动台进行汽车零部件等振动试验存在试验周期长，成本高等问题，采用有限元方法构建了一套虚拟电动振动系统。建立了电磁系统以及动圈的有限元模型，实现了从动圈电流输入到振动台台面加速度输出的全过程虚拟仿真。对动圈所受的电磁驱动力进行理论分析与有限元仿真发现，它在空间上是非均匀分布的，而且力的大小和运动位置有关，呈现出明显的非线性规律。最后，利用该虚拟振动系统进行实例仿真，仿真表明，在动圈的运动过程中，其所受电磁驱动力的非线性会引起台面加速度输出信号的谐波失真问题。相对于线性电磁模型，该虚拟振动系统提供了更真实的振动环境。
Abstract：There are some problems such as long test period and high cost for shakers to carry out the vibration test of automobile parts.A virtual electrodynamic vibration system was constructed by the finite element method.The finite element model was established,and the whole process from the input of the moving coil current to the acceleration output of the shaker was realized.The theoretical analysis and finite element simulation on the electromagnetic driving force of the moving coil have found that the force is unevenly distributed in space and its magnitude is related to the position of motion which exhibits obvious nonlinear property.Using the virtual vibration system for case simulations,the simulation results show that the non-linearity of the electromagnet driving force acting on the moving coil can cause the harmonic distortion of acceleration output signals.Compared with thelinear electromagnetic model,the virtual vibration system can provide a more accurate and realistic virtual vibration environment.