Mechanics of Structured Materials

总体目标：我的研究计划通过开发新的分析理论、计算模型和实验技术，在多个长度尺度上研究结构材料的力学。我的研究出版物反映了工程科学的这种整体方法。首要目标是了解材料的内部结构对其宏观热机械性能的影响。 最新进展：我的HQP和我(A)对周期结构中的线性和非线性波的传播进行了分析和计算研究，包括无序和无序的周期结构，以及结构材料的断裂。利用渐近方法和计算模型，我们证明了对于线性波，非线性波可以在禁止的频率范围内传播。我们展示了基于点阵核心的轻质、坚硬和安静的夹芯板设计，具有优越的隔波特性，而不会牺牲结构刚度或增加质量；(B)发展了基于统计力学的应力分析理论和分子模型，并结合连续介质描述来阐明基于聚合物刷子的软质活性材料中刺激相关结构的演变及其对机械应力的影响。 目标：(A)在中尺度上，我们试图解决这个问题：建筑材料的动态断裂韧性如何取决于其拓扑结构？ (B)在纳米尺度上，我们寻求建立在我们早期工作的基础上，以解决：外部刺激(温度、湿度、pH、光的变化)引起的排除体积效应如何与固定在柔性底物上的末端系留聚合物链中的底物弹性相互作用？ 意义和影响：拟议的研究将导致在介观尺度上具有优异的抗动态载荷能力的新型结构材料。这对于设计轻质、刚性、坚固、坚韧和安静的交通和能源行业的结构部件是很重要的。了解软性活性材料的纳米力学将影响将它们用作执行器和传感器的广泛的技术应用。 HQP培训：该项目将在未来五年内培训2名博士、2名硕士和9名UG实习生。

Overarching goal: My research program investigates the mechanics of structured materials at multiple length scales by developing novel analytical theory, computational models, and experimental techniques. My research publications reflect this holistic approach to engineering science. The overarching goal is to understand the influence of a material's internal structure on its macroscopic thermo-mechanical properties. Recent progress: My HQP and I have (a) Pursued analytical and computational studies on linear and nonlinear wave transmission in periodic structures with and without disorder and on fracture of structured materials. Using asymptotic methods and computational modelling, we showed that nonlinear waves can propagate in a forbidden frequency range for linear waves. We have demonstrated lattice-core based light, stiff and quiet sandwich panel designs with superior wave insulation characteristics, without sacrificing structural stiffness or increasing mass; (b) Developed analytical theories for stress and molecular models based on statistical mechanics coupled with a continuum description to elucidate the evolution of stimuli-dependent structure and its influence on mechanical stress in soft active materials based on polymer brushes. Objectives: (a) On the mesoscale we seek to address the question: How does the dynamic fracture toughness of an architected material depend on its topology? (b) On the nanoscale we seek to build on our earlier work to address: How does the external stimulus (change in temperature, humidity, pH, light) induced excluded volume effects interact with substrate elasticity in end-tethered polymer chains anchored to a flexible substrate? Significance and Impact: The proposed research will lead to novel structured materials with superior dynamic loading resistance on mesoscale. This is important for designing light, stiff, strong, tough and quiet structural components in transportation and energy industries. Understanding the nano mechanics of soft active materials will impact a wide array of technological applications using them as actuators and sensors. HQP training: This program will train 2 PhDs; 2 MASc; 9 UG interns over the next five years.