3D Multiscale Modelling and Characterisation of the Coupled Electromechanical Behaviour of Novel Smart Piezoelectric Nanocomposites

新型智能压电纳米复合材料耦合机电行为的 3D 多尺度建模和表征

• 批准号: RGPIN-2018-03804
• 负责人: Meguid, Shaker
• 金额: $ 6.63万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712625
• 关键词: 3D; Multiscale; Modelling; Characterisation; Coupled

BACKGROUND: The aims of my newly proposed research program are to generate new knowledge to accurately model, characterise and develop the next generation of lightweight smart piezoelectric nanocomposites (SPNCs) for use as sensors, actuators and energy harvesters, with greater understanding of the fundamental parameters that govern their electromechanical behaviour. The new SPNCs are fabricated using preferentially aligned array of nanowires (NWs) with finite interspacing and encased by nanoscopic surface electrodes in an epoxy matrix. Due to their outstanding electromechanical properties, Zinc Oxide and Gallium Nitride NWs are selected. The piezoelectric coefficients define the electromechanical behaviour of NWs and SPNCs; beyond the small field condition, these coefficients are temperature dependent. RESEARCH PROGRAM: The long-term aims are to generate new knowledge leading to new SPNCs' designs and analysis tools, requiring the following short term objectives: 1. Determine the effective mechanical properties and the direct piezoelectric coefficients of a homogenised sensor fiber for the direct piezoelectric effect by applying mechanical strain at constant electric field using novel hybrid molecular dynamics (MD)-density functional theory (DFT) to a NW surrounded by an epoxy matrix. 2. Compute the effective mechanical properties and the converse piezoelectric coefficients of a homogenised actuator fiber for the converse piezoelectric effect using DFT-MD. 3. Determine the bulk electromechanical properties of SPNCs by scaling up a network of the effective sensor fibers developed in Objective 1 using 3D hierarchical multiscale strategy. 4. Compute the bulk electromechanical properties of SPNC by scaling up a network of the effective actuator fibers developed in Objective 2 using modified micromechanics and homogenization schemes and a new network recognition strategy. 5. Conduct extensive experimental work that involves the measurements of the parameters that govern the behaviour of NWs and SPNCs, which will guide the respective atomistic and continuum models and validate their predictions. The largely unknown role of doping, defects, depolarisation and temperature of these wurtzite nanostructures will be examined in Objectives 1-5. SIGNIFICANCE: SPNCs are envisioned to be the building blocks of next generation civil and military applications, characterised by adaptability, multifunctionality and autonomy for sensing, actuating, and energy harvesting. The research will pioneer a technique to characterise the effect of thermo-electro-mechanical loading on the piezoelectric coefficients, overcome the numerous limitations of monolithic piezoceramics, develop highly versatile smart nanocomposites, address anomalies and deficiencies in existing literature, train 66 HQP, and facilitate technology transfer to Canadian industry and military.

背景：我新提出的研究计划的目的是生成新知识，以准确建模，表征和发展下一代的轻型智能压电纳米复合材料（SPNC），以对传感器，执行器和能量收获者使用，并更了解控制其电子力学行为的基本参数。新的SPNC使用优先对齐的纳米线阵列（NWS）制造，并用有限的间隙进行，并用纳米镜面表面电极包裹在环氧基质中。由于其出色的机电特性，因此选择了氧化锌和氮化岩NW。压电系数定义了NWS和SPNC的机电行为；除了小田间条件之外，这些系数取决于温度。 研究计划：长期目的是生成新的知识，从而导致新的SPNC的设计和分析工具，需要以下短期目标： 1。通过使用新型杂交分子动力学（MD）密度功能理论（DFT）在恒定电场上施加机械应变，确定均质传感器纤维的有效机械性能和直接的压电系数，以实现直接的压电效应。 2。使用DFT-MD计算同质化的执行器纤维的有效机械性能和浓度的致电纤维的反向压电系数。 3。通过使用3D层次多尺度策略来扩展目标1中开发的有效传感器纤维的网络来确定SPNC的批量机电特性。 4。通过使用修改的微力学和均质化方案以及新的网络识别策略来扩展目标2中有效执行器纤维的网络来计算SPNC的批量机电特性。 5。进行广泛的实验工作，涉及控制NWS和SPNC行为的参数的测量，这将指导各自的原子和连续模型并验证其预测。这些Wurtzite纳米结构的掺杂，缺陷，去极化和温度的很大未知作用将在目标1-5中检查。 意义：SPNC被设想为下一代民用和军事应用的基础，其特征在于适应性，多功能性和感应，驱动和能量收获的自主权。 The research will pioneer a technique to characterise the effect of thermo-electro-mechanical loading on the piezoelectric coefficients, overcome the numerous limitations of monolithic piezoceramics, develop highly versatile smart nanocomposites, address anomalies and deficiencies in existing literature, train 66 HQP, and facilitate technology transfer to Canadian industry and military.