Design and analysis of functional composites with strain induced magneto-electric coupling

应变诱导磁电耦合功能复合材料的设计与分析

• 批准号: 201201344
• 负责人: Dr.-Ing. Dominik Brands
• 金额: --
• 依托单位: Institut für Mechanik
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/201201344?language=en
• 关键词: Design; analysis; functional; composites; strain

Functional materials with magneto-electric coupling are of high importance with respect to the enhancement and development of functional tools in medical engineering and information technology. But only functional materials, which are characterized by a significantly large magneto-electric coupling, own a reliable relevance. Natural materials do not exhibit this behavior in a technically relevant temperature range. Thus, the design of artificially produced magento-electric materials is of high scientific interest. Within this project magneto-electric composites, which are represented by a piezo-electric matrix with magnetic inclusions, should be analyzed and modeled. Thereby, the modeling of the individual constituents at the microscale as well as the material characterization at the macroscale is of major interest.The focus of the first funding period was the modeling of the macroscopic behavior of magneto-electric composites using numerical homogenization methods. On that account, the development of suitable constitutive descriptions of the magneto-mechanically and electro-mechanically coupled phases was necessary. For a multiscale computational framework, in the context of coupled problems, a suitable definition of the scale transition was defined. The developed methods were used for the simulation of appropriate boundary value problems to analyze the influence of the polarization process of the electric phase on the magneto-electric coupling coefficient.In the second founding period we will focus on the enhancement of the developed models with respect to the prediction of the magneto-electric coupling coefficient in two-phase composites. Therefore, the ferromagnetic material behavior will be described using a variation of the Preisach-model. For the necessary experimental comparison reconstructions of real three-dimensional microstructures are essential. From these reconstructions ordinarily non-periodic discretizations of the boundary result, consequently, the development of weak periodic boundary conditions for the definition of the microscopic boundary value problem is required. Furthermore, the discontinuities across microscopic phase boundaries (imperfect interfaces) should be considered. The numerical results will also be compared to experimental data, in detail we concentrate on the ferroic constitutive laws of the individual phases, the imperfect interfaces and the macroscopic characterization of the coupling coefficient.

磁电耦合功能材料对于医学工程和信息技术中功能工具的增强和发展具有重要意义。但是，只有功能材料，其特征在于一个显着大的磁电耦合，拥有可靠的相关性。天然材料在技术上相关的温度范围内不会表现出这种行为。因此，设计人工生产的磁电材料具有很高的科学价值。在这个项目中，磁电复合材料，这是由一个压电矩阵与磁性夹杂物，应进行分析和建模。因此，在微观尺度上的单个成分的建模以及在宏观尺度上的材料表征是主要的interests.The第一个资金周期的重点是使用数值均匀化方法的磁电复合材料的宏观行为的建模。因此，有必要对磁-机械和电-机械耦合相进行适当的本构描述。对于多尺度计算框架，在耦合问题的背景下，定义了合适的尺度转换的定义。所发展的方法被用于模拟适当的边值问题，以分析电相的极化过程对磁电耦合系数的影响。在第二个创建阶段，我们将重点加强所发展的模型在预测两相复合材料中的磁电耦合系数。因此，将使用Preisach模型的变体来描述铁磁材料行为。为了进行必要的实验比较，重建真实的三维微观结构是必不可少的。从这些重建通常非周期性离散的边界结果，因此，弱周期性边界条件的定义的微观边界值问题的发展是必需的。此外，应考虑微观相界（不完美界面）的不连续性。数值计算结果也将与实验数据进行比较，详细地，我们集中在各个相的铁性本构律，不完美的界面和耦合系数的宏观表征。