3D Multiscale Modelling and Characterisation of the Coupled Electro-Mechanical Behaviour of Nanocomposites

背景技术背景：由于碳纳米管具有优异的力学和物理性能，已成为热固性聚合物的优良剪裁剂。少量（0.1-0.2重量%）的CNT分散到聚合物基质中可能导致其机械和电学性质的显著变化，从而导致增加的功能。对CNT-聚合物界面的性质和力学的清楚理解将使我们能够充分利用CNTs的优异性能。研究方向：我们将对多功能纳米复合材料的机电耦合行为进行原创性和基础性研究。从理论上讲，我们将：（1）制定和实施3D多尺度方法，该方法通过新的原子内聚区定律将分子动力学和特别适应的有限元（FE）联系起来，以解释界面条件，（2）采用微观力学和均匀化技术来确定纳米复合材料的有效机械性能，以解释不同聚合物体系的界面条件，（3）使用代表性的单元尺寸和周期性边界条件进行导电网络的3D Monte Carlo模拟（MC），以及（4）整合（2）和（3）以开发新的3D多尺度FE-MC模拟，以研究不同CNT负载的导电网络的耦合机电行为。在实验上，我们将通过测量分子间界面强度、机械和电学性质以及应变电导率来验证模型。重要性：这项研究将产生新的知识，导致更好地理解界面在纳米复合材料中的作用;解决文献中存在的一系列异常现象;导致下一代多功能纳米复合材料的开发;并为41 HQP在纳米工程，多尺度建模和耦合场问题方面提供极好的培训机会。

BACKGROUND: In view of their outstanding mechanical and physical properties, carbon nanotubes (CNTs) have emerged as excellent tailoring agents for thermoset polymers. The dispersion of small amounts (0.1-0.2 wt%) of CNTs into a polymeric matrix could lead to dramatic changes in its mechanical and electrical properties, leading to added functionalities. A clear understanding of the nature and mechanics of CNT-polymer interface will enable us to fully harness the outstanding properties of CNTs.RESEARCH PROGRAM: We will conduct original and fundamental studies of the coupled electro- mechanical behaviour of multifunctional nanocomposites. Theoretically, we will: (1) Formulate and implement 3D multiscale methodology that links molecular dynamics and specially adapted finite element (FE) via novel atomistic cohesive zone law to account for interface condition, (2) Employ micromechanical and homogenization techniques to determine the effective mechanical properties of nanocomposites accounting for the interface condition for different polymer systems, (3) Conduct 3D Monte Carlo simulations (MC) of percolating conductive networks using a representative cell size and periodic boundary conditions, and (4) Integrate (2) & (3) to develop new 3D multiscale FE-MC simulations to study the coupled electro-mechanical behaviour of percolated networks for varied CNT loading. Experimentally, we will validate the models by measuring intermolecular interface strength, mechanical & electrical properties and strain-conductivity. SIGNIFICANCE: This research will generate new knowledge leading to a greater understanding of the role of the interface in nanocomposites; address a host of anomalies existing in literature; lead to the development of the next generation multifunctional nanocomposites; and provide excellent training opportunities for 41 HQP in nanoengineering, multiscale modelling, and coupled field problems.