Pattern-Changing Instabilities and Giant Magnetostriction in Periodic Magnetoelastic Composites

周期性磁弹性复合材料中的图案变化不稳定性和巨磁致伸缩

• 批准号: 1068769
• 负责人: Pedro Ponte Castaneda
• 金额: $ 10.98万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1068769&HistoricalAwards=false
• 关键词: Pattern; Changing; Instabilities; Giant; Magnetostriction

The research objective of this grant is to elucidate the effect of a certain type of "pattern-changing" instabilities in magneto-elastic composites with periodic microstructures in order to achieve much larger magnetostrictive strains than have been possible to date in these systems. In the purely mechanical context, it is known that these pattern-changing instabilities, where the deformation in the composite abruptly changes (or bifurcates) from the usual one-cell periodic pattern to a new, lower energy deformation pattern involving collective interactions between the cells, is typically associated with a "soft" mode of deformation, where small changes in the applied stress can lead to large strains. Building on earlier work, theoretical tools will be designed for modeling efficiently the possible appearance of these instabilities and the macroscopic response of the composite in the post-bifurcation "soft" regime. These tools will then be used to design magneto-elastic composites that are capable of significantly larger ("giant") magnetostrictive strains than have been possible to date. This research will result in novel and highly efficient multi-field modeling techniques, which will be of broad application to large classes of active material systems, and will lend themselves to numerical implementation in FEM codes. Improvements in the modeling of magneto-elastic composites and in the design of microstructures leading to large magnetostrictive strains should lead to enhanced performance of these materials in many industrial applications, ranging from adaptive tuned vibration absorbers in automotive suspension systems to artificial muscles in the robotics industry, as well as phononic and photonic bandgap switches. The research will be conducted synergistically with educational and outreach activities.

该赠款的研究目标是阐明具有周期性微结构的磁弹性复合材料中某种类型的“模式改变”不稳定性的影响，以实现比这些系统中可能达到的磁性菌株更大的磁性菌株。在纯粹的机械环境中，众所周知，这些变化的不稳定性，其中复合物中的变形突然改变（或分叉）从通常的单细胞周期性模式变为新的，较低的能量变形模式，涉及细胞之间的集体相互作用，通常与“软”变形方式相关联，其中所施加的应力的较小变化会导致较大的应变。在早期工作的基础上，理论工具将设计用于对这些不稳定性的可能外观进行建模，并在后分类后的“软”制度中对复合材料的宏观响应进行建模。然后，这些工具将用于设计能够明显更大（“巨型”）磁性菌株的磁弹性复合材料，而不是迄今为止的可能性。这项研究将导致新颖且高效的多场建模技术，该技术将广泛应用于大量的活性材料系统，并将自己用于FEM代码中的数值实现。磁弹性复合材料的建模和显微结构设计的改进，导致大型磁性菌株应在许多工业应用中导致这些材料的性能提高，范围从自适应调谐的振动吸收器范围从汽车悬浮系统中的自适应调谐振动吸收器到机器人行业的人造肌肉到机器人行业的人造肌肉，以及声音和光子带隙开关。该研究将通过教育和外展活动协同进行。