Multiscale modeling of magnetosensitive materials using experimental microstructural data

使用实验微观结构数据对磁敏材料进行多尺度建模

• 批准号: 237999972
• 负责人: Professor Dr.-Ing. Markus Kästner
• 金额: --
• 依托单位: Professur für Numerische und Experimentelle Festkörpermechanik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/237999972?language=en
• 关键词: Multiscale; modeling; magnetosensitive; materials; using

The overarching goal of the present project is the modeling and simulation of magnetoactive materials, to investigate their structure-property relationships. Special attention is paid to the modeling of magnetorheological elastomers (MREs) on multiple scales. Starting from the constitutive properties of the polymer matrix as well as the magnetic particles and accounting for the microstructural arrangement of the latter, the effective macroscopic material behavior is predicted. For both, the micro- as well as the macroscale, a continuum-based modeling approach is used. This multiscale strategy allows for a cooperation with other groups of the priority program and helps to provide an in-depth understanding of the structure-property relationships of hybrid magnetic materials. Eventually, the gained insights will help to improve the applicability of these materials in the fields of actuators and sensors.For the numerical solution of magneto-mechanical homogenization problems, simulation techniques based on the finite element method (FEM) are developed within this project. This allows for arbitrary shapes and distributions of the magnetizable particles on the microscale. Furthermore, it is possible to consider a complex nonlinear behavior of the individual constituents. Within the simulation, the local magnetic and mechanical fields are resolved explicitly, so that the generally inhomogeneous magnetization of the particles and the non-affine deformation of the polymer matrix is taken into account in the modelling approach. The related macroscopic behavior of the MREs follows from an energetically consistent scale transition process. In the first two funding periods, the principal focus was on the investigation of MREs consisting of magnetically soft particles and a purely elastic matrix. Hence, the effective behavior of such materials was free of any hystereses, i. e. completely reversible. The main objective of the third funding period is the investigation of MRE with magnetic and mechanical hysteresis effects which results from the magnetically hard behavior of the particles and the viscoelastic properties of the matrix. To this end, a detailed characterization of the magnetic and mechanical behavior of the particles and the polymer matrix is planned in cooperation with experimental working groups of the priority program. Based on the constitutive properties of the components and detailed information of the microstructure, the effective behavior of the MREs is predicted. The parameters of a macroscopic constitutive model, which describes the coupled magneto-mechanical properties of MRE, are identified by means of the predicted effective curves. Finally, it is possible to simulate the macroscopic behavior of realistic samples and components and to compare the results with experimental data.

本项目的首要目标是磁活性材料的建模和模拟，以研究它们的结构-性能关系。对磁流变弹性体(MRE)的多尺度建模进行了研究。从聚合物基质和磁性颗粒的本构性质出发，考虑了磁性颗粒的微观结构排列，预测了材料的有效宏观行为。对于微观和宏观两个尺度，都使用了基于连续介质的建模方法。这一多尺度战略允许与优先计划的其他小组合作，并有助于深入了解混合磁性材料的结构-性质关系。最终，所获得的见解将有助于提高这些材料在执行器和传感器领域的适用性。为了解决磁力均匀化问题的数值解，本项目开发了基于有限元方法的模拟技术。这允许可磁化颗粒在微尺度上的任意形状和分布。此外，还可以考虑单个成分的复杂的非线性行为。在模拟中，局部磁场和机械场被显式分解，从而在建模方法中考虑了颗粒的普遍不均匀磁化和聚合物基质的非仿射变形。MREs的相关宏观行为源于能量上一致的尺度转变过程。在头两个资助期，主要重点是研究由磁性软颗粒和纯弹性基质组成的磁爆震荡。因此，这种材料的有效行为没有任何滞后，即完全可逆。第三个资助期的主要目标是研究具有磁滞效应和机械滞后效应的磁流变液，这是由于颗粒的磁硬行为和基质的粘弹性性质造成的。为此，与优先方案的实验工作组合作，计划对颗粒和聚合物基质的磁性和机械行为进行详细表征。基于构件的本构特性和微观结构的详细信息，对磁流变液的有效行为进行了预测。利用预测的有效曲线对描述磁流变液磁力耦合特性的宏观本构模型的参数进行了辨识。最后，可以模拟真实样品和组件的宏观行为，并将结果与实验数据进行比较。