Microstructure-Based Multi-Physics Characterisation and Modelling of Magnetorheological Elastomers

基于微结构的磁流变弹性体多物理场表征和建模

• 批准号: EP/H016619/2
• 负责人: Zaoyang Guo
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FH016619%2F2
• 关键词: Microstructure; Based; Multi; Physics; Characterisation

Magnetorheological elastomers (MREs) are multi-phase, multi-functional composite materials with magnetisable particles suspended in a non-magnetic elastomer solid. The mechanical properties of MREs can be reversibly changed and controlled almost instantaneously by altering an externally applied magnetic field. For this reason MREs are regarded as a class of smart materials and hold promise in many industrial applications (e.g., adaptive tuned vibration absorbers, stiffness tuneable mounts, and artificial muscles). However, a generalised constitutive model for MREs is lacking due to the difficulties to model precisely MREs' nonlinear and anisotropic behaviour (including the nonlinear ferroelectric properties of the particles, the nonlinear mechanical response of the matrix, and the anisotropy caused by the material microstructure and the external magnetic field), making it currently difficult to simulate and optimise the design of MRE applications in a virtual environment. Given the importance of computer aided engineering in today's design methodology, this is clearly a significant obstacle preventing widespread exploitation of MREs. Furthermore, a fundamental understanding of the relationship between microstructure and macroscale behaviour in MREs is essential before improving and tailoring MREs for a specific application can be achieved. This project is concerned with modelling and characterisation of the magnetomechanical behaviour of MREs in the finite deformation regime in order to ultimately understand the structure-property relation of MREs. The goal is to develop the first realistic microstructure-based macroscale magnetomechanical constitutive model for MREs via homogenisation of the multi-physics simulation of representative volume element (RVE) model at the microscale.In the proposed research, true 3D microstructures of various MRE materials will be obtained by MicroCT to develop computational magnetomechanical RVE models of MREs. Macroscale complete magnetomechanical constitutive models will be derived and calibrated through homogenisation of the RVE models. Comprehensive experiments will be implemented and the measured microscale deformation (via MicroCT) and macroscale (homogenised) deformation (via Digital Image Correlation (DIC) system) will be employed to verify the developed microstructure-based RVE models and macroscale models respectively. The models will then be applied to a real engineering problem, the design optimisation of the MRE rubber air springs.This project hinges upon a unique combination of analytical, numerical and experimental work and it will deliver (i) magnetomechanical experimental protocols for MRE materials; (ii) microstructure-based RVE models for MRE materials; (iii) a multi-physics nonlinear FEM solver for magnetomechanical problems; and (iv) a general macroscale constitutive modelling framework applicable to any multi-physics phenomena. The successful outcome of this project will have significant direct impact on both industrial and academic communities.

磁流变弹性体（MRE）是一种多相、多功能的复合材料，它是在非磁性弹性体固体中悬浮有可磁化颗粒。通过改变外部施加的磁场，MRE的机械性能几乎可以瞬间可逆地改变和控制。出于这个原因，MRE被认为是一类智能材料，并且在许多工业应用中有希望（例如，自适应调谐振动吸收器、刚度可调支架和人造肌肉）。然而，由于难以精确地模拟磁流变液的非线性和各向异性行为，因此缺乏一个通用的磁流变液本构模型（包括粒子的非线性铁电性质、基体的非线性力学响应以及材料微结构和外磁场引起的各向异性），使得目前难以在虚拟环境中模拟和优化MRE应用的设计。考虑到计算机辅助工程在当今设计方法中的重要性，这显然是阻止广泛利用MRE的一个重大障碍。此外，MRE的微观结构和宏观行为之间的关系的基本理解是必不可少的，然后才能改善和定制MRE的特定应用程序可以实现。该项目关注的是MRE在有限变形状态下的磁力学行为的建模和表征，以最终了解MRE的结构-性能关系。本研究的目标是通过对代表性体积元（RVE）模型的多物理场模拟在微观尺度上的均匀化，建立第一个基于微观结构的磁流变弹性体宏观磁力学本构模型，利用MicroCT获得各种磁流变弹性体材料的真实三维微观结构，建立磁流变弹性体的计算磁力学RVE模型。宏观完整的磁力本构模型将通过RVE模型的均匀化来推导和校准。将实施全面的实验，并将采用测量的微尺度变形（通过MicroCT）和宏观尺度（均匀化）变形（通过数字图像相关（DIC）系统）分别验证开发的基于微观结构的RVE模型和宏观尺度模型。该项目是分析、数值和实验工作的独特结合，将提供（i）MRE材料的磁力实验方案;（ii）MRE材料的基于微结构的RVE模型;（iii）磁力问题的多物理场非线性有限元求解器;（iv）MRE橡胶空气弹簧的设计优化。以及（iv）适用于任何多物理现象的一般宏观尺度本构建模框架。该项目的成功结果将对工业界和学术界产生重大的直接影响。