Three-Dimensional Modeling of Magnetic Shape Memory Alloys

这项资助的研究目标是建立一个通用的三维模型，能够预测磁性形状记忆合金在任何类型的磁和/或机械载荷下的应力-应变-磁化行为。磁性形状记忆合金是独一无二的，因为当它们暴露在磁场中时，当内部马氏体变体重新定向时，它们会经历可恢复的应变。与这些材料建模相关的挑战包括，但不限于，在任何载荷下确定变量何时重定向以及重定向的方向。作为迈向三维模型的第一步，任何二维磁机械加载的完整模型都是必需的。为了更好地了解这些合金并辅助建模，将对所有具有压应力和/或磁场的性质不同的双轴加载情况进行实验测试。这项研究的材料、方法和结果将被整合到首席研究员教授的自适应材料和系统课程中，为学生提供独特的磁性自适应材料培训。该项目的成果将在一年一度的弗拉格斯塔夫科学节期间向技术会议上的同行、北亚利桑那大学的学生和教职员工以及普通民众展示，并在期刊和会议记录上发表。最后，这项工作将创造一种预测磁性形状记忆合金在复杂载荷下的行为的方法，这将使工程师深入了解这些合金的潜在应用，并为包括磁性形状记忆合金在内的设备的设计提供一个强大的工具。

The research objective of this grant is to establish a general three-dimensional model capable of predicting the stress-strain-magnetization behavior of magnetic shape memory alloys under any type of magnetic and/or mechanical loading. Magnetic shape memory alloys are unique because they experience a recoverable strain when exposed to a magnetic field as internal martensitic variants reorient. The challenges associated with modeling these materials include, but are not limited to, determining when the variants reorient and the direction of reorientation under any loading. As an initial step towards a three-dimensional model, a complete model for any two-dimensional magneto-mechanical loading is needed. In order to better understand these alloys and to assist with the modeling, all qualitatively different biaxial load cases with compressive stress and/or magnetic field will be tested experimentally. The materials, methodologies, and results of this research will be integrated in the Adaptive Materials and Systems course taught by the principal investigator, providing students with unique training in magnetically adaptive materials. The results of this project will be presented to peers at technical conferences, to students and faculty at Northern Arizona University, and to the general population during the annual Flagstaff Festival of Science, as well as published in journals and conference proceedings. Finally, this work will create a means of predicting the behavior of magnetic shape memory alloys subject to complex loads, which will give engineers insight into potential applications of these alloys and a robust tool for the design of devices that include magnetic shape memory alloys.