Download or read book Development of a New System for Detecting Fatigue Cracks in Steel Bridges written by J. R. Barton and published by . This book was released on 1973 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nondestructive detection and characterization of fatigue cracks during field inspection of steel bridge structures are put in perspective in terms of the magnitude of the problem and viable nondestructive methods. The results of nondestructive method assessment, selection, evaluation, and experimental confirmation are presented in detail. Developed as a useful and effective solution to the problem, the inspection system consists of two independent, complementary, lightweight, battery-powered electronic instruments-an acoustic crack detector (ACD), which uses ultrasonic principles, automatic signal analysis, and a simple digital data display for rapid survey, and a magnetic crack definer (MCD), which uses magnetic principles and a simple ON-OFF light data display for defining the precise location and crack length. The features and functioning of the equipment are briefly described, and laboratory and field demonstrations, presentations, and field inspections are reviewed. The technical basis for equipment development, including equipment concepts, is summarized.
Download or read book Strain based Fatigue Crack Monitoring of Steel Bridges Using Wireless Elastomeric Skin Sensors written by Jian Li and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue cracks that develop in steel highway bridges under repetitive traffic loads are one of the major mechanisms that degrade structural integrity. If bridges are not appropriately inspected and maintained, fatigue cracks can eventually lead to catastrophic failures, in particular for fracture-critical bridges. Bridge owners, such as state Departments of Transportation (DOTs), typically rely on trained bridge inspectors to visually inspect steel bridges for fatigue cracking so that appropriate repairs can be applied before cracks reach critical sizes. However, visual inspections can be prone to error due to inconsistent skills and result interpretation among inspectors. Advanced approaches for detecting and/or monitoring of fatigue cracks have been investigated in both the structural health monitoring (SHM) and nondestructive testing (NDT) communities. An important challenge with the existing methods is their reliance on extensive human operations to collect critical measurements in the field, making it challenging to implement long-term continuous crack monitoring of steel bridges. In this report, a wireless elastomeric skin sensor is proposed to monitor fatigue cracks in steel bridges. The wireless elastomeric skin sensor consists of three components: (1) a large-area strain-based skin sensor, termed soft elastomeric capacitor (SEC), serving as the fundamental sensing unit for crack monitoring; (2) a newly-developed data acquisition (DAQ) board for measuring the small capacitance change from the SEC under fatigue cracking; and (3) a wireless sensing platform (Xnode) for transferring SEC’s signal from the DAQ board to the base station in the field. Validation of the wireless elastomeric skin sensor is completed through several numerical and experimental investigations of the fundamental sensing unit, SEC, for fatigue crack monitoring. We validate the integrated monitoring system through a field deployment on a steel highway bridge. Compared with the off-the-shelf DAQ system, the newly-developed sensor board can collect SEC measurements with better noise performance. More importantly, the developed sensor board can be integrated with the wireless sensing platform Xnode to transfer the collected SEC signals to the base station through wireless communication. This capability will significantly improve the flexibility of the monitoring system by reducing the cabling work in the field. As a result, the integration of wireless capacitive sensing and the SEC technology enables a wireless elastomeric skin sensor for fatigue sensing of steel bridges. Data collected in the field showed that, through the trigger-based sensing mechanism, the wireless crack monitoring system was able to collect data continuously and autonomously from the SEC sensors and the strain gauge under the traffic loading. By processing the raw measurements using the proposed algorithm, Crack Growth Indices (CGIs) of each monitored location could be continuously collected and statistically monitored for long-term monitoring of fatigue cracks of steel bridges. Several further development needs were identified to achieve more robust, accurate, and flexible crack monitoring. First, an improved understanding of the SEC sensor behavior under folded configuration is needed to strategically adjust the CGI algorithm when the SECs are attached to corners and joints. Second, the capacitance sensor board is currently based on analogy circuits, meaning the balancing and shunt calibration are performed manually. Converting the analog circuit to a digital one will enable software control and automation of these processes, hence greatly improving the efficiency and flexibility of the wireless sensing. Third, deployment of the sensor network at more diverse structural configurations and more extensive analyses of long-term field data are necessary to ensure adaptability of the proposed CGI algorithm.
Download or read book FHWA Publications written by United States. Federal Highway Administration and published by . This book was released on 1984 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distortion induced Fatigue Cracking in Steel Bridges written by John W. Fisher and published by Transportation Research Board. This book was released on 1990 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feasibility of Nondestructive Crack Detection and Monitoring for Steel Bridges written by United States. Federal Highway Administration and published by . This book was released on 2012 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This multi-year study was designed to identify and evaluate nondestructive evaluation systems and techniques capable of detecting surface and subsurface cracks, including growing cracks, as small as 0.01 inches in length or depth in bridge structures. The focal point of the study was on fatigue-prone and high-stress critical locations of steel bridge girders. Such locations include those with high concentrations of stress, particularly at steel weldments and sharp corners"--Technical report documentation p.
Download or read book Structural Materials Technology written by Paul E. Hartbower and published by CRC Press. This book was released on 2020-08-23 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of papers presented in the NDT Conference held on February 20-23, 1996 at San Diego, California. The conference provided an opportunity to share experience and provide additional input to the Federal Highway Administration.
Download or read book Structural Materials Technology written by Robert J. Scancella and published by CRC Press. This book was released on 1994-01-01 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Public Roads written by and published by . This book was released on 2000 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book FHWA Nationally Coordinated Program of Highway Research Development and Technology Annual Progress Report Fiscal Year 1993 written by and published by . This book was released on 1993 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nationally Coordinated Program of Highway Research Development and Technology Annual Progress Report Fiscal Year 1994 written by and published by . This book was released on 1995 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Department of Transportation and Related Agencies Appropriations for 1999 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Department of Transportation and Related Agencies Appropriations and published by . This book was released on 1998 with total page 2014 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bridge Maintenance Safety Management Life Cycle Sustainability and Innovations written by Hiroshi Yokota and published by CRC Press. This book was released on 2021-04-20 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations contains lectures and papers presented at the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), held in Sapporo, Hokkaido, Japan, April 11–15, 2021. This volume consists of a book of extended abstracts and a USB card containing the full papers of 571 contributions presented at IABMAS 2020, including the T.Y. Lin Lecture, 9 Keynote Lectures, and 561 technical papers from 40 countries. The contributions presented at IABMAS 2020 deal with the state of the art as well as emerging concepts and innovative applications related to the main aspects of maintenance, safety, management, life-cycle sustainability and technological innovations of bridges. Major topics include: advanced bridge design, construction and maintenance approaches, safety, reliability and risk evaluation, life-cycle management, life-cycle sustainability, standardization, analytical models, bridge management systems, service life prediction, maintenance and management strategies, structural health monitoring, non-destructive testing and field testing, safety, resilience, robustness and redundancy, durability enhancement, repair and rehabilitation, fatigue and corrosion, extreme loads, and application of information and computer technology and artificial intelligence for bridges, among others. This volume provides both an up-to-date overview of the field of bridge engineering and significant contributions to the process of making more rational decisions on maintenance, safety, management, life-cycle sustainability and technological innovations of bridges for the purpose of enhancing the welfare of society. The Editors hope that these Proceedings will serve as a valuable reference to all concerned with bridge structure and infrastructure systems, including engineers, researchers, academics and students from all areas of bridge engineering.
Download or read book Department of Transportation and Related Agencies Appropriations for 2001 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Department of Transportation and Related Agencies Appropriations and published by . This book was released on 2000 with total page 1884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Department of Transportation and Related Agencies Appropriations for 2000 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Dept. of Transportation and Related Agencies Appropriations and published by . This book was released on 1999 with total page 1798 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Load Carrying Capacity of Bridges written by Organisation for Economic Co-operation and Development and published by Organization for Economic Co-operation and Development ; [Washington, D.C. : sold by OECD Publications and Information Center]. This book was released on 1979 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nondestructive Evaluation of Aging Bridges and Highways written by Society of Photo-optical Instrumentation Engineers and published by SPIE-International Society for Optical Engineering. This book was released on 1995 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Department of Transportation and Related Agencies Appropriations for 1997 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Department of Transportation and Related Agencies Appropriations and published by . This book was released on 1996 with total page 1304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
