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，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这种工程科学的整体方法。总体目标是了解材料的内部结构对其宏观热机械性能的影响。最近进展：我和我的HQP进行了(a)有和无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断裂的分析和计算研究。利用渐近方法和计算模型，我们证明了非线性波可以在线性波的禁止频率范围内传播。我们已经展示了基于格芯的轻质、刚性和安静夹层板设计，具有卓越的波绝缘特性，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，并结合连续体描述，以阐明基于聚合物刷的软活性材料中依赖刺激的结构的演变及其对机械应力的影响。目标：(a)在中尺度上，我们寻求解决这个问题：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值、光的变化）诱导的排除体积效应如何与锚定在柔性基板上的末端系绳聚合物链中的基板弹性相互作用？意义与影响：本研究将带来具有优异的中尺度动载荷抗力的新型结构材料。这对于交通运输和能源行业设计轻、硬、强、韧、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将其用作致动器和传感器的广泛技术应用。HQP培训：该项目将培养2名博士；2:德文;未来5年招聘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.