Drone-laser-computer aided system for remote monitoring of critical structures

The structures and infrastructures are decaying, and they need regular monitoring for performance and safety assessment. One of the factors that can be an indicator of the poor performance of the structures is vibrations exceeding acceptable values specified in the safety codes. However, current existing methods require inspectors to climb the structures to install sensors on these critical zones. These sensors are contact sensors and they need a reference point from where to measure. Installation of the sensors can be unsafe for inspectors, take time, lead to huge expenses, and sometimes these critical structures don\u27t even have access. Drones are used along with the cameras to inspect the condition of the structures and infrastructures with the images captured from the structure. But they only provide image-based information and decisions. The data are visual and does not provide any physical of data like displacement that can be obtained by contact sensors. In order to be able to monitor structures safely, accurately, and inexpensively, this research develops a new drone-laser-computer aided system to collect the displacement values from the structures remotely. In this project, a camera-drone-laser system is built with wireless communication between the added sensors and the computer system. This wireless communication system helps the system to fly without tether. New computer vision algorithm is developed to obtain the reference-free displacement values by integrating both the laser and the camera dynamic measurement of the structure while correcting the drone hovering in a full, integrated system. This research introduces the new generation for SHM which enables reference-free monitoring of structural dynamic responses of structures, increasing safety and accuracy of operations

Low-cost Efficient Wireless Intelligent Sensor (LEWIS) for Engineering, Research, and Education

Sensors have the capability of collecting engineering data and quantifying environmental changes, activities, or phenomena. Civil engineers lack of knowledge in sensor technology. Therefore, the vision of smart cities equipped with sensors informing decisions has not been realized to date. The cost associated with data acquisition systems, laboratories, and experiments restricts access to sensors for wider audiences. Recently, sensors are becoming a new tool in education and training, giving learners real-time information that can reinforce their confidence and understanding of scientific or engineering new concepts. However, the electrical components and computer knowledge associated with sensors are still a challenge for civil engineers. If sensing technology costs and use are simplified, sensors could be tamed by civil engineering students. The researcher developed, fabricated, and tested an efficient low-cost wireless intelligent sensor (LEWIS) aimed at education and research, named LEWIS1. This platform is directed at learners connected with a cable to the computer but has the same concepts and capabilities as the wireless version. The content of this paper describes the hardware and software architecture of the first prototype and their use, as well as the proposed new LEWIS1 (LEWIS1 beta) that simplifies both hardware and software, and user interfaces. The capability of the proposed sensor is compared with an accurate commercial PCB sensor through experiments. The later part of this paper demonstrates applications and examples of outreach efforts and suggests the adoption of LEWIS1 beta as a new tool for education and research. The authors also investigated the number of activities and sensor building workshops that has been done since 2015 using the LEWIS sensor which shows an ascending trend of different professionals excitement to involve and learn the sensor fabrication.Comment: 19 pages, 17 figures, 7 table

Bridge Construction Monitoring using LIDAR for Quantified, Objective Quality-Control Quality-Assurance (QOQCQA)

Transportation infrastructure construction quality control and quality assurance demands construction monitoring by field inspectors. Currently, these inspectors monitor infrastructure by measuring and photographing structures. These tasks allow them to assess any correction decision during construction or to inform about the quality of the construction process for the future. In order to promote and objective decisions obtained during infrastructure construction, the proposed research project developed and implemented a methodology to measure construction progress and compared it with the designed 3D shape, quantifying the difference. This proposed project includes implementation for the development of DOT standards that could be added in near future bridge construction documents. The New Mexico Department of Transportation (NMDOT) showed a strong interest in this topic. The experience of the PIs on bridge design and construction, field inspection, and LIDAR technology was integrated in order to evaluate the results with impact both in research and in industry. Specifically, the research results outline recommendations about standards for implementation of technology in specifications for NMDOT or other DOTs

Framework for risk-based management and safety of railroad bridge infrastructure using wireless smart sensors (WSS)

To increase overall profitability, add capacity to rail operations to meet projected needs, and comply with new federal regulations on bridge safety, North American railroads are exploring means and methods to improve the management of their bridge networks. Current maintenance, repair, and replacement (MRR) decisions are informed by bridge inspections and ratings. Inspection and rating practices recommend observing the response of bridges under revenue traffic. However, an objective relationship between bridge responses and the impact to railroad operations has yet to be established. Moreover, measuring responses while trains are on the bridge can be quite challenging and sometimes may not be possible. As a result, current MRR decisions are not optimal and in general conservative, prioritizing safety to overcome the uncertainty of consequences of inaction. If the consequences of MRR decisions could be better determined, then the railroads could more effectively allocate their limited resources. This dissertation addresses this issue by developing an approach for consequence-based management of bridge networks, adopted from the field of seismic risk assessment, for making MRR decisions on a network-wide basis. The proposed framework assesses bridge service state condition based on fragility relations. Fragility curves are developed relating bridge responses under revenue service traffic to service condition limit states. Additionally, this research conducted specific Structural Health Monitoring (SHM) campaigns for railroad bridges employing Wireless Smart Sensors (WSS). Wireless strain gages installed in the rail measured real-time trainloads and speeds, while wireless accelerometers and magnetic strain gages measured associated bridge responses. The sensing system was deployed and validated on multiple railroad bridges in North America under different types of traffic and capacity. The measured bridge data can be used to update periodically the fragilities to have more accurate estimates of the bridge condition. The expenses associated with these service conditions estimate the total costs of a given MRR policy. In this way, MRR decisions can be prioritized minimizing negative consequences to railroad operations. This framework provides a consistent approach for intelligent management of railroad bridges, and more specifically, for the prioritization of railroad bridge MRR decisions. Using this framework the rail owner can identify the most efficient use of a limited budget while maintaining safe railroad operations

Strategies for Prioritizing Needs for Accelerated Construction after Hazard Events

There is a need for rapid and responsive infrastructure repair and construction after natural disaster events such as hurricanes, wildfires, and tornadoes. These natural disasters often shut down basic infrastructure systems, as experienced recently in several Region 6 states as well as in other states around the country. Accelerated construction practices are often used in these situations to speed up the traditional, and often slow, project delivery process. However, after a natural disaster, several and different types of transportation infrastructure components are in need of inspection, rehabilitation or reconstruction, and transportation agencies are challenged with the task of prioritizing these accelerated projects. This study conducted an extensive literature review of current accelerated methods, infrastructure prioritization practices, and institutional barriers. Interviews with professionals from the transportation industry, including both private and public services, were conducted. Significant input from the railroad industry was used to compare private and public transportation systems responses after disasters. The results of this survey were used to quantify the importance of the accelerate methods and prioritization criteria, and which are the barriers to implement a prioritization model. Lastly, a decision support tool for prioritizing needs for accelerated construction after disaster events, specifically hurricanes and flooding, which commonly affect Region 6, was developed using the data collected

Current Research Topics: Railroad Bridges and Structural Engineering

Railroad infrastructure must be maintained safely and reliably for both owners and users. Railroad bridge expenditures in particular represent about 10% of the annual capital investment for Class I railroads in the United States (U.S.). Due to the lack of flexibility of railroad networks, railroads cannot afford not to repair or replace bridges that should be either partially upgraded or completely renovated. If they fail to do so, maintenance expenses and/or structural failure could cause railroads to lose money that would have been saved if part of it had been properly budgeted and used in the first place. Beyond these financial concerns associated with railroad bridge management, railroads (which are private commercial enterprises in the U.S.) are widely recognized for placing a high priority on safety. Academia, government, and railroad bridge engineering agencies have, over the years, all formally studied a variety of railroad bridge research topics. In the past, workshops have assisted railroad institutions toward directing research efforts based on the current needs of the railroad bridge structural engineering community. This report is the result of a new survey-based study entitled “Current Research Topics: Railroad Bridges and Structural Engineering.” The lead author of this report planned and conducted the survey during the 2009-2010 academic years, and comprised the results and findings during 2011. Research topics were selected and prioritized following the results of a detailed telephone survey conducted with sixteen experts on railroad bridges and structural engineering in North America. This report includes a literature review that was developed to follow up on topics discussed during the course of the survey interviews. In addition, other focused conversations with key professionals in both the railroad bridges and structural engineering communities (including experts on associated technologies from academia and industry) have been incorporated into this report. The increased nationwide attention toward high-speed railroads has also been addressed. Finally, new federal regulations affecting railroad bridge management in the U.S. have been examined and included. This survey-based study identifies the management of railroad bridges as a primary concern for railroad bridge structural engineers today. Field assessment, especially as it relates to bridge capacity, is of particular interest. The nearterm implementation of Structural Health Monitoring (SHM) into railroad bridge management has been identified as a potential tool for railroad bridge management. Finally, current and future research in this and other related areas is briefly discussed and proposed. In summary, this report identifies current structural engineering research topics of interest for railroad bridges in North America. In particular, the railroad bridge structural engineering community finds the assessment of bridge performance under traffic loading by using emerging SHM techniques to be a top research interest. As a consequence, SHM implementation for railroad bridges management should be given high priority for research and development.Association of American Railroads (AAR) Technology Scanning ProgramMax Zar ScholarshipSEI ASCE O. H. Amman Research FellowshipTalentia Fellowship (Junta de Andalucia, Spain

Mossbauer and magnetization studies of amorphous NdFeB compositionally modulated thin films

Several NdFeB compositionally modulated thin films are studied by using both conversion electron Mossbauer spectra and SQUID (superconducting quantum-interference-device) magnetometry. Both the hyperfine fields and the easy magnetization magnitude are not correlated with the modulation characteristic length (lambda) while the magnetization perpendicular to the thin-film plane decreases as lambda increases. The spectra were recorded at room temperature being the gamma rays perpendicular to the substrate plane. The magnetization measurements were recorded by using a SHE SQUID magnetometer in applied magnetic fields up to 5.5 T and in the temperature range between 1.8 and 30 K