PFI-TT: Multi-Frequency Acoustic Device for Rapid Infrastructure Damage Diagnostics

这一创新-技术转化伙伴关系(PFI-TT)项目的更广泛影响/商业潜力是确保关键民用基础设施(如管道和桥梁)的安全运行，使用更可靠和更具成本效益的手段监测其健康状况。由于极端天气事件的数量和规模越来越大，老化的基础设施的性能令人担忧；意外故障导致交通严重中断，并对人类生活和环境造成负面影响。幸运的是，声发射可以“监听”基础设施中的裂缝，并在缺陷可见之前检测到它们。其创新之处在于建立了一种低成本、低功率的声发射装置，用于检测具有数百个传感器的基础设施，并在最早的状态下检测损伤起始。传感器的技术是微电子机械系统，MEMS。通过从基础设施中收集大量可靠的数据，大规模制造的MEMS声发射设备可能会将技术提升到一个新的水平。其目的是用能够迅速告知结构状态和安全的海量传感器来测量基础设施。当美国的大多数结构系统都配备了MEMS声发射设备时，可以在故障的最早阶段检测到故障的开始，并采取必要的预防措施，以防止更大的费用。拟议的项目旨在将集成了隔音能力的多频率MEMS声发射设备转变为可现场部署的技术。声发射是一种基于探测由于裂纹扩展或滑坡等活动缺陷或运动而传播的弹性波的无损评估方法。它以检测损伤的起始、精确定位损伤的位置、定性评估损伤的严重程度以及使用模式识别工具对损伤模式进行分类而闻名。然而，目前的声发射传感器体积庞大、价格昂贵，并且受背景噪声的影响很大；它们需要复杂的后处理来理解信号的特征，这延误了决策过程。MEMS传感器是使用微机械技术制造的，这种技术允许大规模制造具有可重复的固有特性。MEMS声发射装置将由多个超窄带宽MEMS压电谐振器连接成阵列，通过精心选择的频率的建设性干扰来放大总响应。为了了解频率相关的损伤模式和严重程度，可以很容易地将信号分解成其频率。为了区分人工噪声源和有源结构缺陷，MEMS声发射设备将与宽带弹性超材料相结合，以屏蔽减少数据无线传输的无用信号。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this Partnerships for Innovation-Technology Translation (PFI-TT) project is to ensure the safe operation of critical civil infrastructure (such as pipelines and bridges) using a more reliable and cost-effective means of monitoring their health. Subjected to an increasing number and magnitude of extreme weather events, the performance of aging infrastructure is a concern; Unexpected failures cause significant disruption in transportation and negatively influence human lives and the environment. Fortunately, acoustic emission, can “listen” for cracks in the infrastructure and detect defects before they are visible. The innovation is to build a low-cost and low-power acoustic emission device for instrumenting infrastructures with hundreds of sensors and detecting the damage initiation at the earliest state. The technology for the sensors is micro-electro-mechanical systems, MEMS. Mass manufactured MEMS acoustic emission devices may take the technology to the next level by collecting big and reliable data from infrastructures. The aim is to instrument infrastructures with voluminous sensors that can rapidly inform about the structural state and safety. When the majority of structural systems in the US are instrumented with MEMS acoustic emission devices, the initiation of failure can be detected at its earliest stage and necessary precautions can be taken, preventing greater expenses. The proposed project aims to transition multi-frequency MEMS acoustic emission devices integrated with noise isolation capability into a field-deployable technology. Acoustic Emission is a nondestructive evaluation method based on detecting the propagating elastic waves due to active defects or movements such as crack growth or landslides. It is well-known for detecting the initiation of damage, pinpointing its location, qualitatively assessing the severity of damage, and classifying the damage mode using pattern recognition tools. However, current acoustic emission sensors are bulky, expensive, and significantly influenced by background noise; They require complex post-processing to understand the signal characterization, which delays the decision-making process. MEMS sensors are manufactured using micromachining techniques, that allow mass manufacturing with repeatable intrinsic characteristics. MEMS acoustic emission devices will be built by multiple super-narrow bandwidth MEMS piezoelectric resonators connected in an array such that the total response is amplified by the constructive interference of carefully selected frequencies. The signal can easily be decomposed into its frequencies in order to understand the frequency-dependent damage modes and severity. To distinguish artificial noise sources from active structural defects, the MEMS acoustic emission device will be coupled with broadband elastic metamaterials to block unwanted signals for the reduced-data wireless transfer.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.