Physics of Nonlinear Mechanics

该奖项支持理论和计算研究和教育，其中统计和计算物理技术应用于固体力学中的各种非线性问题，主要但不限于断裂。需要解决的一些特殊问题包括：裂缝如何选择它们的方向？石墨烯的断裂特性是什么？为什么用胶带制造石墨烯的方法有效？橡胶在高速拉伸时的表现如何？这种行为如何影响断裂？在构建光学纳米结构的实际尝试中，粘附和摩擦的规律是什么？这些问题来自物理学和工程学的许多不同分支学科，但通过基础理论技术、一套通用的数值工具和材料研究的一个总体主题统一起来，该主题寻求回答：宏观现象如何从微观基础推导出来？这项研究的部分内容可能具有工程应用价值。在完成第二版凝聚态物理教材后，PI将为世界各地的教师提供支持。他将完成一本关于如何进行科学研究的本科教材。他将使用统计物理学的技术来分析高风险公立学校考试的数据，并开发评估学校和教师的新方法。他将继续监督他所在大学的科学和数学教师的准备工作，以及复制德克萨斯大学奥斯汀分校项目的快速增长的全国大学网络。该奖项支持理论研究和教育，目的是了解材料的行为如何遵循基本的物理定律。特别是，PI旨在理解机械行为的原子尺度基础，例如固体如何拉伸、弯曲、流动和断裂。断裂理论中的一个突出问题是裂纹如何选择其运动方向。当裂缝移动迅速时，这个问题尤其困难，当裂缝是一场可能发生也可能不会发生在人口稠密地区的地震时，这个问题尤其重要。关于如何进行的一些提示来自橡胶破裂的实验，PI将积极地追求这些提示。另一个问题与石墨烯的形成有关，石墨烯是未来电子设备的一种很有前途的候选材料。它最初是通过用胶带拉住石墨而获得的。为什么这样一个简单的过程有效呢？它能被优化成非常大的石墨烯条吗？PI会试着回答这个问题。该提案的第二部分涉及教育。PI刚刚完成了一篇关于凝聚态物理整个领域的研究生论文，并将提供支持材料。他正在完成一篇关于如何进行科学研究的本科论文，并将提供支持材料。他正在将统计物理学的技术应用于高风险考试分数的分析，这可能会影响这些分数如何被用来评估教师、学校和学区。

Technical SummaryThis award supports theoretical and computational research and education where techniques from statistical and computational physics are applied to a variety of nonlinear problems in the mechanics of solids, mainly but not exclusively involving fracture.Some particular questions to be addressed include: How do cracks choose their direction? What are the fracture properties of graphene? Why does the method of creating graphene with tape work? How does rubber behave when stretched at high rates, and how does this behavior affect fracture? What are the laws of adhesion and friction that govern practical attempts to build optical nanostructures? These questions come from many different subdisciplines of physics and engineering, but are unified by underlying theoretical techniques, by a common set of numerical tools, and by an overarching theme of materials research which seeks to answer: How do macroscopic phenomena follow from microscopic foundations?Parts of this research may have engineering applications. The PI will provide support to instructors around the world after completion of a second edition of a textbook on condensed matter physics. He will complete a textbook for an undergraduate course on how to conduct scientific research. He will use techniques from statistical physics to analyze data from high-stakes public school tests and develop new ways to assess schools and teachers. He will continue to oversee the preparation of science and mathematics teachers at his home institution, as well as a rapidly growing national network of universities replicating the UT Austin program.Nontechnical SummaryThis award supports theoretical research and education with the aim of understanding how the behavior of materials follows from underlying physical laws. In particular, the PI aims to understanding the atomic-scale underpinnings of mechanical behavior, such as how solids stretch, bend, flow, and fracture. One of the outstanding problems in the theory of fracture is how cracks choose which direction to go. The problem is particularly difficult when the cracks are moving fast, and particularly important when the crack is an earthquake that may or may not hit a densely populated area. Some hints at how to proceed come from experiments on the rupture of rubber, and the PI will actively pursue these hints. Another problem concerns the formation of graphene, a promising candidate material for electronic devices of the future. It was first obtained by pulling on graphite with adhesive tape. Why does such a simple process work? Can it be optimized to make very large strips of graphene? The PI will try to answer that.A second part of the proposal concerns education. The PI is just finishing a graduate text on the whole field of Condensed Matter Physics, and will provide supporting materials. He is finishing an undergraduate text on how to conduct scientific research, and will provide supporting materials. He is applying techniques from statistical physics to the analysis of high-stakes test scores, which may influence how these scores are used to evaluate teachers, schools, and districts.