Abstract

This paper employed a nonlinear constitutive relation to describe the mechanical behavior of sintered neodymium iron boron (NdFeB) and studied the dynamic damage of NdFeB in the electromagnetic buffer. The systematic research on the constitutive model of NdFeB was yet studied. To end this, a suite of dynamic tests was implemented using a Split Hopkinson Pressure Bar (SHPB) system to obtain the compressive behavior at different strain rates of NdFeB. Referred to as Zhu-Wang-Tang (ZWT), the damage-modified constitutive model used herein was fitted by the experimental data, so that a set of ZWT model parameters for the tested materials was achieved. Then the incremental expression of the constitutive model was formulated and further embedded into ABAQUS via the VUMAT subroutine interface to establish the dynamic model of the electromagnetic buffer, followed by calculated. Finally, the damage peak of NdFeB was optimized according to the interval uncertain optimization method. The detailed assessments showed that the damage peak appeared in the inner side of the right-most permanent magnet, and its value was greatly reduced after optimization.

摘要

本文采用非线性本构关系描述烧结钕铁硼（NdFeB）的力学行为，研究了钕铁硼在电磁缓冲器中的动态损伤。尚未对钕铁硼的本构模型进行系统研究。为此，使用分裂霍普金森压力棒 (SHPB) 系统实施了一套动态测试，以获得不同应变率下的 NdFeB 的压缩行为。将本文所用的损伤修正本构模型称为竹王堂（ZWT），通过实验数据拟合，从而获得了一组被测材料的ZWT模型参数。然后将本构模型的增量表达式通过VUMAT子程序接口嵌入到ABAQUS中，建立电磁缓冲器的动态模型，其次是计算。最后根据区间不确定优化方法对钕铁硼的损伤峰进行优化。详细评估表明，损伤峰值出现在最右侧的永磁体内侧，优化后其值大大降低。