Composite materials play important roles in multifunctional applications, and thus, the diagnosis of damage patterns in composite materials becomes crucial to avoid critical events" such as structural or functional failures. The impact of an individual damage in composite materials has been extensively studied, however, the interaction of defects/cracks, which leads to critical fracture paths, has not been understood well. In this paper, we develop a Bayesian estimation based statistical analysis technique that estimates the damage pattern of a composite material, in particular, the relative positions of defects in the material, by measuring its through-thickness dielectric properties. We first explain the fundamental dielectric principle that leads to the detection of defect patterns. A capacitance model is then built to measure the material permittivity, and the relationship between the dielectric permittivity and relative positions are found using COMSOL Multiphysics. The interaction effects between defects observed in the simulation are interpreted using the fundamental dielectric principle. A Bayesian estimation based statistical analysis model is then developed to estimate the relative positions of defects in composite materials from the measured global dielectric properties.
Unmanned aerial vehicles (UAVs) play increasing roles in structure health monitoring. With growing mobility in modern Internet-of-Things (IoT) applications, the health monitoring of mobile structures becomes an emerging application. In this paper, we develop a UAV-carried vision-based monitoring system that allows a UAV to continuously track and monitor a mobile infrastructure and transmit back the monitoring information in real- time from a remote location. The monitoring system uses a simple UAV-mounted camera and requires only a single feature located on the mobile infrastructure for target detection and tracking. The computation-effective vision-based tracking solution based on a single feature is an improvement over existing vision-based lead-follower tracking systems that either have poor tracking performance due to the use of a single feature, or have improved tracking performance at a cost of the usage of multiple features. In addition, a UAV-carried aerial networking infrastructure using directional antennas is used to enable robust real-time transmission of monitoring video streams over a long distance. Automatic heading control is used to self-align headings of directional antennas to enable robust communication in mobility. Compared to existing omni-communication systems, the directional communication solution significantly increases the operation range of remote monitoring systems. In this paper, we develop the integrated modeling framework of camera and mobile platforms, design the tracking algorithm, develop a testbed of UAVs and mobile platforms, and evaluate system performance through both simulation studies and field tests.
Our nation’s infrastructural systems are crumbling. The deteriorating process grows over time. The physical aging of these vital facilities and the remediation of their current critical state pose a key societal challenge to the United States. Current sensing technologies, while well developed in controlled laboratory environments, have not yet yielded tools for producing real-time, in-situ data that are adequately comprehensible for infrastructure decision-makers. The need for advanced sensing technologies is national because every municipality and state in the nation faces infrastructure management challenges. The need is critical because portions of infrastructure are reaching the end of their life-spans and there are few cost-effective means to monitor infrastructure integrity and to prioritize the renovation and replacement of infrastructure elements. New advanced sensing technologies that produce cost-effective inspection and real-time monitoring data, and that can also help or aid in meaningful interpretation of the acquired data, therefore will enhance the safety in regard to the public on structural integrity by issuing timely and accurate alert data for effective maintenance to avoid disasters happening. New advanced sensing technologies also allow more informed management of infrastructural investments by avoiding premature replacement of infrastructure and identifying those structures in need of immediate action to prevent from catastrophic failure. Infrastructure management requires that once a structural defect is detected, an economical and efficient repair be made. Advancing the technologies of repairing infrastructure elements in contact with water, road salt, and subjected to thermal changes requires innovative research to significantly extend the service life of repairs, lower the costs of repairs, and provide repair technologies that are suitable for a wide range of conditions. All these new technologies will provide increased lifetimes, security, and safety of elements of critical infrastructure for the Nation’s already deteriorating civil infrastructure. It is envisioned that the Nation should look far beyond: not only should we efficiently and effectively address current problems of the aging infrastructure, but we must also further develop next-generation construction materials and processes for new construction. To accomplish this ambitious goal, we must include process efficiency that will help select the most reliable and cost-effective materials in construction processes; performance and cost will be the prime consideration for selections construction materials based on life-cycle cost and materials performance; energy efficiency will drive reduced energy consumption from current levels by 50 % per unit of output; and environmental responsiveness will achieve net-zero waste from construction materials and its constituents. Should it be successfully implemented, we will transform the current 21st century infrastructure systems to enable the vital functioning of society and improve competitiveness of the economy to ensure that our quality of life remains high.
We conduct a comparative study of approaches for optimal sensor placement from the fields of control engineering
and civil engineering. The widely used civil engineering approaches such as EI and MAC have limitations due to the negligence of damping parameters. On the other hand, control engineering approaches do not consider the key parameters of interest in civil structures. We study the maximization of estimation performance of key structural characteristics from impulse response data, using approaches from both fields to unveil the pros and cons of each.
Conference Committee Involvement (9)
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, Civil Infrastructure, and Transportation XV
22 March 2021 | Online Only, California, United States
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, Civil Infrastructure, and Transportation XIV
27 April 2020 | Online Only, California, United States
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, Civil Infrastructure, and Transportation XIII
4 March 2019 | Denver, Colorado, United States
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, Civil Infrastructure, and Transportation XII
5 March 2018 | Denver, Colorado, United States
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, Civil Infrastructure, and Transportation XI
26 March 2017 | Portland, Oregon, United States
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, and Civil Infrastructure X
21 March 2016 | Las Vegas, Nevada, United States
Structural Health Monitoring and Inspection of Advanced Materials, Aerospace, and Civil Infrastructure IX
9 March 2015 | San Diego, California, United States
Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security VIII
10 March 2014 | San Diego, California, United States
Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security VII
10 March 2013 | San Diego, California, United States
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