CAREER: Experimental Investigation of Highly Nonlinear Granular Crystals for the Development of New Mechanical Systems and Acoustic Metamaterials

这个学院早期职业发展(CALEAR)项目的研究目标是创造和理解基于工程设计的有序颗粒晶体的新超材料。超材料是人工合成的系统，其基本成分(例如球形颗粒)以精确的几何结构排列，呈现出其他自然系统所没有的特性。它将通过实验研究应力波如何在这些新材料中传播，并将开发数值和分析模型来预测它们的行为。它将研究波在界面上的行为，并将研究离散效应和周期性、无序和局部化的相互作用，创造与其他物理现象的相似之处。研究这些新材料所提供的理解将有助于创造新的设备，如可调谐的声学透镜、减振器、能量捕获器和致动器。这项工作的社会影响可以通过潜在的发现将影响日常生活的新系统来确定(即成像/手术、保护系统和通信中的信号转换/再分配的新声学方法)。它还将提供一个很好的教育平台：创造和理解新的机械系统需要学习如何在基础物理和想象力之间找到深度的平衡，激励年轻一代进行开箱即用的思考。它将让研究生、本科生和高中生参与几项合作活动，将开创性的研究与实际应用和可申请专利的设备的开发相结合。它将特别强调本科教育，激励女性和代表不足的群体走向科学。这项工作的多学科方面将促进与其他研究机构、行业和更广泛的社区的合作。拟议的计划将开设两个新的学术课程，并将举办具有强烈国际重要性的暑期学校。

The research objective of this Faculty Early Career Development (CAREER) project is creating and understanding new metamaterials based on engineered, ordered granular crystals. Metamaterials are artificially composite systems, having their fundamental components (for example spherical grains) arranged in precise geometrical structures, that present properties not found in other natural systems. It will study how stress waves propagate in these new materials with experiments, and will develop numerical and analytical models to predict their behavior. It will research wave behavior at interfaces and will study the interplay of discrete effects and periodicity, disorder and localization, creating parallels with other physical phenomena. The understanding provided by studying these new materials will allow the creation of novel devices like tunable acoustic lenses, vibration absorbers, energy traps and actuators.The societal impact of this work can be identified with the potential discovery of new systems that will affect everyday life (i.e. new acoustic methods for imaging/surgery, protective systems and signal transformation/redistribution in communication). It will also offer a great educational platform: creating and understanding new mechanical systems requires learning how to balance in depth fundamental physics with imagination, inspiring young generation to ?think out-of-the-box?. It will engage graduate, undergraduate, and high school students in several cooperative activities combining groundbreaking studies with the development of practical applications and patentable devices. It will particularly emphasize undergraduate education, motivating women and underrepresented groups toward science. The multidisciplinary aspects of this work will foster collaborations with other research institutions, with industry and with the broader community. The proposed plan will create two new academic courses and will organize summer schools with strong international emphasis.