Mechanics of Structured Materials

总体目标：我的研究项目通过开发新的分析理论，计算模型和实验技术，研究结构材料在多个长度尺度上的力学。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。 近期进展：我和我的HQP（a）对具有和不具有无序的周期性结构中的线性和非线性波传输以及结构材料的断裂进行了分析和计算研究。使用渐近方法和计算模型，我们表明，非线性波可以传播的禁止频率范围内的线性波。我们已经证明了基于网格芯的轻质、刚性和安静的夹层板设计具有上级波浪绝缘特性，而不牺牲结构刚度或增加质量;（B）发展了基于统计力学的应力和分子模型的分析理论，并结合连续描述，以阐明刺激的演变，非独立结构及其对基于聚合物刷的软活性材料中的机械应力的影响。 目的：（a）在介观尺度上，我们试图解决的问题：如何动态断裂韧性的建筑材料取决于它的拓扑结构？ (b)在纳米尺度上，我们寻求建立在我们早期的工作，以解决：如何外部刺激（温度，湿度，pH值，光）的变化诱导排除体积效应与基板弹性在端栓系聚合物链锚定到一个灵活的基板？ 意义和影响：所提出的研究将导致新的结构材料与上级动态加载阻力在介观尺度上。这对于在交通和能源行业中设计轻、硬、强、坚韧和安静的结构部件非常重要。了解软活性材料的纳米力学将影响使用它们作为致动器和传感器的广泛技术应用。 HQP培训：该计划将在未来五年内培训2名博士; 2名硕士; 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.