Collaborative Research: Novel NDE/SHM Approach Based on Highly Nonlinear Dynamics

这项研究将开发一项实验研究计划，以创建基于高度非线性孤立波的材料和结构的无损评估和结构健康监测(NDE/SHM)的新范式。这项拟议的研究利用高度非线性系统提供的可调性，开辟了一个新的理论和实验研究领域，旨在：a)了解高度非线性振子和线性结构之间的耦合；b)跨尺度检测缺陷：从微观到宏观水平；c)评估给定系统中施加的应力；d)通过数值模拟来表征材料的机械性能，定制传播过程中的脉冲属性(逆方法)；e)设计新的、因此具有专利的应力波产生和检测的致动器/传感器技术。在过去的二十年中，弹性应力波(在音速和超声波范围内)在无损检测/结构分析中的研究和应用因其能够评估材料的弹性性质和损伤的存在而蓬勃发展。高度非线性波动理论的最新发现和发展及其数值和实验验证为NDE/SHM领域提供了一种新的工具。工程系统的稳健性对于避免灾难性故障至关重要，因为灾难性故障可能会对环境造成严重后果，可能会导致人员伤亡，并产生数以吨计的拆迁废物。因此，能够在早期阶段准确检测缺陷或表征给定结构的力学性能，对于国家-S的可持续性、经济增长和安全至关重要。通过拟议的研究，我们计划深入了解高度非线性波与材料和结构的耦合，为将该技术转化为可行的商业应用提供了直接机会，大大改进了用于NDE/SHM的最先进的驱动/传感技术。这项工作建立在匹兹堡大学和加州理工学院的互补专业知识基础上，并将在这两个机构之间建立坚实的研究合作。该计划将培训研究生和本科生以一种新的方法来解决可持续工程问题。

This research will develop an experimental research program to create a new paradigm for Non Destructive Evaluation and Structural Health Monitoring (NDE/SHM) of materials and structures based on Highly Nonlinear Solitary Waves (HNSWs). The proposed research leverages on the tunability provided by highly nonlinear systems to open up a new field of theoretical and experimental investigations aimed at: a) understanding the coupling between a highly nonlinear oscillators and linear structures; b) detecting defects across scales: from the micro- to the macro-scopic level; c) evaluating applied stress in a given system; d) characterizing the mechanical properties of materials tailoring the pulse properties during propagation (inverse approach) aided by numerical modeling, and e) designing new, and therefore patentable, actuators/sensors technology for stress wave generation and detection. In the last two decades researches and applications of elastic stress waves (both in the sonic and ultrasonic range) for NDE/SHM have thrived owing to their capability of assessing the elastic properties of materials and the presence of damage. The recent discovery and development of the highly nonlinear wave theory and its numerical and experimental validation offer a new tool to the NDE/SHM community. The soundness of engineering systems is essential to avoid catastrophic failures that may be accompanied by severe consequences for the environment, can lead to the loss of human life, and produce tonnage of demolition waste. It is therefore of paramount importance to the nation?s sustainability, economy growth and safety that NDE/SHM, to be able to accurately detect defects at early stages or to characterize the mechanical properties of a given structure. With the proposed research we plan to delve in the fundamental understanding of highly nonlinear waves coupling with materials and structures, offering a direct opportunity to transfer the technology in viable commercial applications much improved over the state-of-the-art actuating/sensing technology for NDE/SHM. The work builds on complementary expertise at the University of Pittsburgh and the California Institute of Technology Caltech and will establish a solid research collaboration between the two institutions. The program will train graduate and undergraduate student to a new approach to sustainable engineering solutions.