Abstract The dynamic mechanical properties of magnetorheological plastomers (MRPs) were investigated by using a Split Hopkinson Pressure Bar (SHPB) equipped with an electromagnetic accessory. Both the SHPB and rheological test indicated the mechanical properties of MRPs increased with strain rate, which demonstrated the typical rate dependent stiffening performance. With strain rate increased from 1580 s−1 to 7900 s−1, the maximum stress of MRPs increased from 31 MPa to 66 MPa. MRPs also exhibited a magnetic strengthening behavior due to the MR effect. Keeping the strain rate at 6500 s−1, the maximum stress increased 19.8 MPa as the magnetic flux density increased from 0 to 480 mT and the increase rate of maximum stress reached to 34%. Moreover, a high-speed camera was also used to capture the deformation of MRPs in both low and high strain rates. Based on the above results, a possible mechanism was proposed to investigate the dynamic mechanical properties of the MRPs. The synergistic effect between the magnetic field dependent particle structure evolution and polymer chain deformation were responded for the MR behavior and strain rate stiffening characteristic, respectively.

中文翻译：

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高应变速率下磁流变塑性体的动态力学性能

摘要 使用配备电磁附件的分裂式霍普金森压力棒 (SHPB) 研究了磁流变塑性体 (MRPs) 的动态力学性能。SHPB 和流变测试均表明 MRP 的机械性能随应变速率增加，这证明了典型的速率相关硬化性能。随着应变速率从 1580 s-1 增加到 7900 s-1，MRPs 的最大应力从 31 MPa 增加到 66 MPa。由于 MR 效应，MRP 还表现出磁强化行为。将应变速率保持在 6500 s-1，随着磁通密度从 0 增加到 480 mT，最大应力增加 19.8 MPa，最大应力增加率达到 34%。此外，还使用高速相机来捕捉低应变率和高应变率下 MRP 的变形。基于上述结果，提出了一种可能的机制来研究 MRP 的动态力学性能。磁场相关的粒子结构演化和聚合物链变形之间的协同效应分别响应于 MR 行为和应变率硬化特性。