Distributed Sensors for Damage Detection and Health Monitoring of Civil Infrastructure

本项目的主要目的是了解一种新设计的用于钢筋混凝土结构应变测量和裂缝检测的传感器的灵敏度，通过对一个大型结构的测试来验证其性能，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对高灵敏度、高分辨率、低成本、坚固耐用的要求，研制了一种新型同轴电缆(分布式传感器)。这种新型传感器在内部和外部导体之间使用了更灵活和更具渗透性的介电层，提高了商业通信电缆对RC构件裂缝检测的灵敏度。增加了一个荷载传递机构，将外部扰动的方向从纵向变形改变为横向压碎，从而提高了拉索受拉反射系数的测量灵敏度。几个传感器都是自行设计和制造的，用标准仪器进行了校准，最后用大型梁柱组件进行了验证，证明了其优越的性能。该项目涉及多学科和美日合作。作为UMR高中生暑期计划的一部分，这将是对K-12学生的展示。

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.