Distributed Sensors for Damage Detection and Health Monitoring of Civil Infrastructure

该项目的主要目标是了解新设计的用于钢筋混凝土（RC）结构应变测量和裂缝检测的传感器的灵敏度，通过大型结构测试验证其性能，并将其性能和成本与分布式光纤传感器进行比较。为满足民用基础设施结构健康监测中对高灵敏度、高分辨率、低成本、坚固耐用的关键要求，研制了一种新型同轴电缆（分布式传感器）。新型传感器提高了商用通信电缆的灵敏度，用于RC构件的裂纹检测，在内外导体之间使用更灵活和更渗透性的介质层。附加的载荷传递机制将外界扰动的方向由纵向变形改为横向破碎，从而使索在张力作用下的反射系数测量更加灵敏。几个传感器在内部设计和制造，用标准仪器校准，最后用大型梁柱组件验证其优越的性能。该项目涉及多学科和美日合作。它将作为UMR高中学生暑期项目的一部分，向K-12学生展示。

The primary objectives of this project are to understand the sensitivity of a newly designed sensor for strain measurement and crack detection in reinforced concrete (RC) structures, to validate its performance by testing of a large-scale structure, and to compare its performance and cost with those of distributed fiber-optic sensors. A new coaxial cable (distributed sensor) is developed to meet the critical requirements for high sensitivity and resolution, low cost, and ruggedness in the structural health monitoring of civil infrastructure. The new sensor improves the sensitivity of commercial communication cables for the crack detection of RC members using more flexible and more permeable dielectric layer between inner and outer conductors. An additional load transfer mechanism is included to alter the direction of external disturbance from longitudinal deformation to transverse crushing, resulting in more sensitive measurement in reflection coefficient of the cable under tension. Several sensors are designed and fabricated in-house, calibrated with standard instruments, and finally validated with a large-scale beam-column assembly for its superior performance. The project involves multidisciplinary and US-Japan collaboration. It will be a showcase to K-12 students as part of the high school students summer program at UMR.