Collaborative Research: Highly Nonlinear Transducer Arrays for Structural Health Monitoring

本课题将研究新型非线性致动器阵列的基本特性及其在土木结构和材料的无损评价（NDE）和结构健康监测（SHM）中的应用。研究人员还将探索使用非线性致动器聚焦和收集弹性能量以及对散装材料进行成像的能力。在这项研究中所包括的阵列的非线性致动器可以产生高度非线性孤立波（HNSW），这是紧凑的非色散应力波与有限的空间维度。这些脉冲的空间维度与波的振幅无关，仅取决于非线性材料的几何形状。HNSW有望改善当前的NDE/SHM设备，因为它们能够支持完全依赖于机械激励的非振荡、高振幅信号。在基本层面上，研究人员旨在了解与不同相邻固体介质相邻的高度非线性致动器阵列的行为。特别是，它们将：（i）研究聚焦非线性波的能力，作为邻近介质的特性的函数，（ii）设计和实施方法以改善信号穿过致动器和邻近介质之间的界面的传输;（iii）确定由于高度非线性致动器的故障而导致的信号功率的限制和性能的劣化。从纯应用的角度来看，该项目将致力于HNSW在结构材料NDE/SHM中的应用。除了对非线性动力学科学界的影响外，拟议的研究将对广泛的工程应用具有战略重要性。本研究的NDE/SHM部分能够提高现有民用和航空航天结构的安全性。收集聚焦弹性能量的能力有可能创造新的、可持续的方式来为小型电子设备和传感器提供动力。这项研究成果将有助于开发用于声学成像的新型换能器阵列，我们研究的成功结果可能会影响生物医学成像社区。一些研究成果和实验将被整合到研究人员的教学组合和推广活动中。这项研究将为所有参与的学生提供多学科培训。由于预计至少有一项专利申请将提交，因此将探索潜在的营销机会。最后，研究成果将通过提交期刊文章和在国际会议上介绍而广泛传播。

This propoject will investigate the fundamental properties and applications of novel arrays of nonlinear actuators for the nondestructive evaluation (NDE) and structural health monitoring (SHM) of civil structures and materials. The investigators will also explore the ability to use the nonlinear actuators for focusing and harvesting elastic energy, and for imaging bulk materials. The arrays of nonlinear actuators included in this study can generate highly nonlinear solitary waves (HNSWs), which are compact non-dispersive stress waves with a finite spatial dimension. The spatial dimension of these pulses is independent of the wave amplitude and dependent only on the nonlinear material's geometry. HNSWs hold promise to improve current NDE/SHM devices because of their ability to support non-oscillatory, high amplitude signals that rely exclusively on mechanical excitations. On a fundamental level, the investigators aim at understanding the behavior of arrays of highly nonlinear actuators adjacent to different neighboring solid media. In particular, they will: (i) study the ability to focus nonlinear waves as a function of the properties of the adjacent media, (ii) design and implement methods to improve transmission of the signal across the interface between the actuators and the adjacent media; (iii) determine the limitations of signal power and the degradation of performance due to failure of the highly nonlinear actuators. From a purely applied perspective, the project will be devoted to the application of HNSWs for the NDE/SHM of structural materials. Besides the impact to the nonlinear dynamics scientific community, the proposed research will have strategic importance to a broad range of engineering applications. The NDE/SHM component of this research enables to increase the safety of existing civil and aerospace structures. The ability to harvest focused elastic energy has the potential to create new, sustainable means to power small electronic devices and sensors. This research outcomes will enable the development of novel transducers arrays for acoustic imaging, the successful outcome of our research could impact the biomedical imaging community.Some of the research outcomes and experiments will be integrated into the investigators' teaching portfolio and into outreach activities. This research will provide multidisciplinary training for all participating students. As the submission of at least one patent application is forecast, potential marketing opportunities will be explored. Finally, the research results will be broadly disseminated through the submission of journal articles and through the presentation at conferences of international audience.