SBIR Phase II: Kaiser Trigger: A Nano-Watt Powered Technology for Ultra-Low Power Fatigue Crack Detection

该项目更广泛的影响/商业潜力是引入新一代低功耗无线传感器的结果，用于检测声发射事件和检测结构中的疲劳损伤。根据美国联邦公路管理局（FHWA）的数据，美国交通基础设施有605,102座正在运营的桥梁，其中66,561座存在结构缺陷。特别是，该项目的疲劳损伤监测技术将首先针对美国的1.8万多座公路桥梁，这些桥梁被分类为？骨折关键?联邦公路管理局这项技术吗?S的超低能耗将使其能够用于低功耗无线传感器，并使其成为解决这一具有挑战性问题的理想方案。该项目的预期效益和商业应用是：(1)一种低成本、易于使用的有效监测机制，可以早期发现并及时修复公路桥梁等基础设施系统的断裂和疲劳损伤；(2)提高公共安全，降低维护成本，延长关键和高价值基础设施系统的使用寿命；(3)监测其他结构的结构健康和完整性的其他商业应用，包括飞机、石油和天然气管道、机械、货物起重机、船舶等。小企业创新研究（SBIR）第二阶段项目涉及基础设施系统的分布式结构健康监测（SHM），特别是公路桥梁。由于结构中疲劳裂纹的产生伴随着声发射（AE）波的传播，因此无线AE传感器可用于检测此类裂纹。然而，声发射检测传感器的一个挑战是高能耗，远远超过电池供电的无线设备的可用能量。因此，传统的声发射检测方法不能与低功耗无线传感器一起使用。本项目采用一种新颖的超低功耗技术对应变进行长期监测。然后，只有当被监测结构的拉伸应变历史表明可能存在疲劳损伤时，才启动声发射监测。此外，该方法利用声发射事件的历史和模式来估计材料疲劳损伤的严重程度。此外，该方法采用多种技术消除了机械噪声对声发射测量的影响，实现了疲劳损伤评估的高可靠性。开发完成后，该方法计划在公路桥梁、机身和管道上进行评估。

The broader impact/commercial potential of this project is the result of introducing a new generation of low-power wireless sensors for detecting Acoustic Emission events and detecting fatigue damage in structures. According to the Federal Highway Administration (FHWA), the US transportation infrastructure has 605,102 operational bridges, of which 66,561 are structurally deficient. In particular, the fatigue damage monitoring technology of the project will initially target the more than 18,000 US highway bridges that are categorized as ?fracture critical? by the Federal Highway Administration. The technique?s ultra-low energy consumption will enable its use in low-power wireless sensors and make it an ideal response to this challenging problem. The anticipated benefits and commercial applications of this project are (1) a low-cost, easy-to-use mechanism for effective monitoring, allowing for early detection and timely repair of fracture and fatigue damage in infrastructure systems such as highway bridges; (2) improved public safety, with reduced maintenance costs and extension of the service life of critical and high-valued infrastructure systems; and (3) additional commercial applications in monitoring the structural health and integrity of other structures, including aircraft, oil and gas pipelines, machinery, cargo cranes, ships, etc.Small Business Innovation Research (SBIR) Phase 2 project addresses distributed structural health monitoring (SHM) of infrastructure systems, particularly highway bridges. Because the creation of fatigue cracks in a structure is accompanied by the propagation of acoustic emission (AE) waves, wireless AE sensors can be used to detect such cracks. However, a challenge of AE detection sensors is high energy consumption, significantly more than the energy available in a battery-operated wireless device. As a result, conventional AE detection methods cannot be used with low-power wireless sensors. This project uses a novel and ultra-low power technique for long term monitoring of strain. Then, AE monitoring is activated only if history of tensile strain in the structure under monitoring suggests likelihood of fatigue damage. In addition, using history and pattern of AE events, the method estimates the severity of fatigue damage in a material. Moreover, the method uses a variety of techniques to eliminate the effects of mechanical noise on AE measurements and achieve a high reliability in fatigue damage assessment. After development, the method is planned to be evaluated on highway bridges, airframes, and pipelines.