Wang Zhenjin, Mori Kotaro, Nakajima Kenya, Narita Fumio
Department of Materials Processing, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan.
Department of Mechanical Engineering, Ibaraki University, Nakanarusawa-cho 4-12-1, Hitachi 316-8511, Japan.
Materials (Basel). 2020 Mar 25;13(7):1494. doi: 10.3390/ma13071494.
Magnetostrictive materials have a wide variety of applications due to their great capability as sensors and energy-harvesting devices. However, their brittleness inhibits their applications as magnetostrictive devices. Recently, we developed a continuous magnetostrictive Fe-Co-fiber-embedded epoxy matrix composite to increase the flexibility of the material. In this study, we fabricated random magnetostrictive Fe-Co short fiber/epoxy composite sheets. It was found that the discontinuous Fe-Co fiber composite sheet has the magnetostrictive properties along the orientation parallel to the length of the sheet. Finite element computations were also carried out using a coupled magneto-mechanical model, for the representative volume element (RVE) of unidirectional aligned magnetostrictive short fiber composites. A simple model of two-dimensional, randomly oriented, magnetostrictive short fiber composites was then proposed and the effective piezomagnetic coefficient was determined. It was shown that the present model is very accurate yet relatively simple to predict the piezomagnetic coefficient of magnetostrictive short fiber composites. This magnetostrictive composite sheet is expected to be used as a flexible smart material.
磁致伸缩材料因其作为传感器和能量收集装置的强大能力而有广泛的应用。然而，它们的脆性限制了其作为磁致伸缩装置的应用。最近，我们开发了一种连续的磁致伸缩铁钴纤维嵌入环氧基质复合材料，以提高材料的柔韧性。在本研究中，我们制备了随机取向的磁致伸缩铁钴短纤维/环氧复合片材。发现不连续的铁钴纤维复合片材在平行于片材长度的方向上具有磁致伸缩性能。还使用磁-机械耦合模型对单向排列的磁致伸缩短纤维复合材料的代表性体积单元（RVE）进行了有限元计算。然后提出了一个二维随机取向磁致伸缩短纤维复合材料的简单模型，并确定了有效压磁系数。结果表明，该模型在预测磁致伸缩短纤维复合材料的压磁系数方面非常准确且相对简单。这种磁致伸缩复合片材有望用作柔性智能材料。
