CAREER: Designing Novel Structural Surfaces for Desired Vibration Transmission and Attenuation

该学院早期职业发展(CALEAR)项目将研究实验和建模技术，使多尺度界面模型的形成成为可能。界面是结构装配中最具柔顺性和耗散性的部位，其性质决定了承重结构的动力响应。对基本治理机制的有限理解导致了对界面属性的描述，这些属性是基于有效性和适用性有限的经验法则。PI的职业目标是调查决定界面属性的因素，并针对结构中所需的振动传递和衰减进行定制。作为该项目的一部分，建立的模型将考虑界面的长度和速度相关的响应，并将用于设计具有可调结构完整性、振动传输和衰减特性的单材料表面。这种新颖的设计方法在振动控制、噪声消除、减震以及能量存储和传输方面开辟了新的途径。本项目将使用最新的激光加工技术，实现可伸缩的表面图案化技术，以制造将被测试和表征的界面。该奖项的教育目标是通过暑期培训计划和科学展览的研究经验，让学生、高中教师和普通公众接触到力学和动力学研究。PI还将根据主动和体验式学习原则开发一门新课程，以解决科学、技术、工程和数学的低保留率问题。活动将把小组活动、多媒体项目、锦标赛风格的设计竞赛和远程访问实验融入到PI的本科生和研究生课程中。这个职业奖项开发多尺度界面模型，并使用它们在承重结构中实现所需的动态响应。将进行独特的原位电子显微镜划痕试验和多尺度试验，以研究位错、裂纹和相干滑移如何影响界面对外部载荷的响应。在这些实验之后，将开发多尺度界面模型。这些模型对宏观尺度界面的可伸缩性将通过测试具有受控长度比例的表面来验证。由于它们的精度、效率和物理基础，这些模型将为涉及界面的复杂的大型结构动力学问题提供有效的解决方案。使用这些界面模型，PI将优化界面以增强阻尼品质因数和宽频带间隙，这两者都调节结构的振动传递和衰减特性。然后，将制造最佳接口，并在瞬变和谐波负载下进行测试。

This Faculty Early Career Development (CAREER) project will investigate experimental and modeling techniques that will enable the formulation of multiscale interface models. Interfaces are the most compliant and dissipative sites in structural assemblies, and their properties govern the dynamic response of load-bearing structures. Limited understanding of underlying governing mechanisms has lead to descriptions of interface properties that are based on empirical laws of limited validity and applicability. The PI's CAREER goal is to investigate the factors determining interface properties, and tailor them for desired vibration transmission and attenuation within a structure. The models formulated as part of this project will account for the length and velocity-dependent response of interfaces and will be employed to design single-material surfaces with tunable structural integrity, and vibration transmission and attenuation characteristics. This novel design approach opens new avenues in vibration control, noise cancellation, shock mitigation, and energy storage and transfer. Latest laser processing techniques enabling scalable surface patterning techniques will be used to fabricate interfaces to be tested and characterized in this project. The educational goal of this award is to expose the students, high school teachers and the general public to contact mechanics and dynamics research through research experiences in summer training programs and scientific exhibitions. The PI will also develop a new curriculum based on active and experiential learning principles to address low retention rates in science, technology, engineering and mathematics. Activities will incorporate group work, multimedia projects, tournament-style design competitions, and remote-access experiments into the PI's undergraduate and graduate courses.This CAREER award develops multiscale interface models, and uses them to achieve desired dynamic response in load-bearing structures. Unique in-situ transmission electron microscope scratch tests, and multiscale experiments will be conducted to study how dislocations, cracks and coherent slip influence the interface response to external loading. Multiscale interface models will be developed after those experiments. Scalability of those models to macroscale interfaces will be validated by testing surfaces with controlled length scales. Thanks to their accuracy, efficiency and physical-basis, those models will provide an effective solution to intractable large-scale structural dynamics problems involving interfaces. Using those interface models, the PI will optimize interfaces for enhanced damping figure of merit, and broad frequency band gaps, both of which regulate vibration transmission and attenuation properties of structures. Optimum interfaces will then be manufactured and tested under transient and harmonic loading.