Wang Huanhuan, Zhang Yongqiang, Tan Zhuhua
School of Mechanical Engineering, Hebei University of Technology, Tianjin 300104, China.
Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China.
Polymers (Basel). 2023 Jan 13;15(2):423. doi: 10.3390/polym15020423.
Low-melting-point alloy (LMPA) was used as an additive to prepare epoxy-resin-based shape memory polymer composites (LMPA/EP SMP), and dynamic mechanical analyzer (DMA) tests were performed to demonstrate the shape memory effect, storage modulus, and stiffness of the composites under different load cases. The composites exhibited an excellent shape recovery ratio and shape fixity ratio, and a typical turning point was observed in the storage modulus curves, which was attributed to the melting of the LMPA. In order to investigate the dynamic deformation mechanism at high strain rates, split Hopkinson pressure bar (SHPB) experiments were performed to study the influence of the strain rate and plastic work on the dynamic mechanical response of LMPA/EP composites. The results showed that there was a saturated tendency for the flow stress with increasing strain rate, and the composites exhibited a typical brittle failure mode at high strain rate. Moreover, an obvious melting phenomenon of the LMPA was observed by SEM tests, which was due to the heat generated by the plastic work at high strain rate. The fundamental of the paper provided an effective approach to modulate the stiffness and evaluate the characteristics of SMP composites.
采用低熔点合金（LMPA）作为添加剂制备了环氧树脂基形状记忆聚合物复合材料（LMPA/EP SMP），并通过动态力学分析仪（DMA）测试来证明复合材料在不同载荷情况下的形状记忆效应、储能模量和刚度。复合材料表现出优异的形状回复率和形状固定率，并且在储能模量曲线中观察到一个典型的转折点，这归因于LMPA的熔化。为了研究高应变率下的动态变形机制，进行了分离式霍普金森压杆（SHPB）实验，以研究应变率和塑性功对LMPA/EP复合材料动态力学响应的影响。结果表明，随着应变率的增加，流动应力存在饱和趋势，并且复合材料在高应变率下表现出典型的脆性破坏模式。此外，通过扫描电子显微镜（SEM）测试观察到LMPA有明显的熔化现象，这是由于高应变率下塑性功产生的热量所致。本文的研究为调节刚度和评估形状记忆聚合物复合材料的特性提供了一种有效方法。
