Download or read book Enhanced Ultrasonic Inspection of Steel Bridge Pin Components written by Margarit G. Lozev and published by . This book was released on 1998 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the development of a technique for obtaining a reliable assessment of the condition of steel bridge pins already determined by ultrasound to contain imperfections. The details of a technique for performing high-definition ultrasonic scans of pins in the field are described. Results demonstrating this technique on specially fabricated calibration pins with actual cracks and actual bridge pins in the field are presented. A mathematical model for tracing the propagation of ultrasonic sound rays is also described. This model can be used as a tool to help interpret scanned images of imperfect pins. The researchers recommend that future research be carried out to develop further the instrumentation equipment and models needed for accurate field assessment of steel bridge pins.

Download or read book Ultrasonic Detection Identification and Sizing of Cracks in Steel Bridge Pins written by John Christian Duke and published by . This book was released on 1999 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes an extension of work previously reported in VTRC 99-R3 "Enhanced Ultrasonic Inspection of Steel Bridge Components" and is a condensation of a thesis.

Download or read book Inspection of Historic Steel Bridges Using Ultrasonic Phased Array written by Alejandra L. Roldan Arcos and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of ultrasonic phased array (UPA) technology for inspection of the trunnion bearing pin of the 100-year old Salmon Bay Bascule Bridge is the focus of this research. To thoroughly investigate the bearing pin, two main objectives are addressed: the development of a UPA system, including the design of a case that uses a Poly Methyl Meth Acrylate (PMMA) material to house the transducer, and the implementation of the system in the field to test the feasibility of the UPA system and its application as a nondestructive testing unit. Two different testing settings are carried out in this research. The first study is performed in a lab-based setting on a mock-up model pin. This model is used as a reference to provide the calibration of the UPA system using the exterior edge, two keyholes, and three diagonal interior grease holes. The second study is performed in a field-based setting on the authentic trunnion bearing pin taken out of service from the Salmon Bay Bridge in Seattle, Washington, currently residing at the Riverside Campus. This pin has three similar diagonal holes, keyholes, and unknown internal defects. Realtime measurements using the UPA system is used to identify the exterior surfaces and the keyholes of the original pin. The results of the inspection of the pins using the UPA system indicate the accuracy of the real-time data taken from the probe measurements. It was limited to seeing perpendicular defects and exterior sides, and could not identify the diagonal grease hole within both pin parts. It did, however, identify the keyholes, and was later verified by visual inspection once the sleeves were removed. The original pin showed no internal defects. For future research in nondestructive testing used in historic trunnion pins, it is recommended to combine this technology with an automatic system that allows the reduction of human interaction with the inspection. A membrane-like surface adaptable to rough faces, along with a constant flow of water between the wedge and surface, would facilitate the need to remove the PMMA case out of the pin to re-apply couplant for inspections. Finally, a modified angled wedge could also be applied within the PMMA case to search for different angled cracking. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152486

Download or read book Phased Array Ultrasonic Steel Corrosion Mapping for Bridges and Ancillary Structures written by Barritt Lovelace and published by . This book was released on 2017 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steel corrosion on bridges and ancillary structures due to environmental effects and deicing chemicals is a serious problem for Minnesota's infrastructure. The ability to detect, locate, and measure corrosion is an important aspect of structure inspection. Accurate thickness measurements and corrosion mapping are essential for determining load capacity of structural members on bridges and ancillary structures. The Minnesota Department of Transportation purchased an OmniScan Phased Array Corrosion Mapping System. Unlike conventional ultrasonic equipment, this system provides detailed three-dimensional images of structural members including the remaining section of members that exhibit corrosion. This gives engineers better tools to visualize and evaluate the condition of bridges than was previously possible. With the future purchase of additional transducers, the OmniScan can also be used for enhanced inspection of welds and bridge pins.

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 Ultrasonic Inspection of Heavy Section Steel Components written by R.W. Nichols and published by Springer. This book was released on 1988-06-30 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bridging the Gap written by and published by DIANE Publishing. This book was released on 2009-02 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers information on the conditions, age and costs to repair and modernize the nation¿s 590,000 bridges as well as key examples showcasing new inspection and construction technologies. Key findings: (1) Within the next 15 years almost half of the nation¿s bridges will exceed 50 years of age, exceeding the life span for which they were designed. Even now, one in five are over 50; (2) With age comes decay. One in four of our bridges are rated as deficient, either in need of repair or in need of widening to handle today¿s traffic; (3) New estimates show that more than $140 billion will be needed to fix them; (4) Soaring construction costs have whittled away the ability of states to address preventive maintenance and new bridge construction. Illustrations.

Download or read book Automation Miniature Robotics and Sensors for Nondestructive Testing and Evaluation written by Yoseph Bar-Cohen and published by . This book was released on 2000 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acceptance Criteria for Ultrasonic Impact Treatment of Highway Steel Bridges written by Rana Tehrani Yekta and published by . This book was released on 2012 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need for rehabilitation of bridges has become a critical challenge due to aging and an increase in traffic loads. Many of these bridges are exceeding their design fatigue life. Since many of these bridges are structurally deficient, they need to be rehabilitated or replaced by a new bridge. The most susceptible and weak parts of steel bridges to cracks and fatigue are the welds, due to the presence of high stress concentrations, tensile residual stresses, and imperfections as a result of the welding process. Inspection and repair of welds are difficult and elimination of welded details is not possible in steel bridge construction. Ultrasonic impact treatment (UIT) is a promising and innovative post-weld treatment (PWT) method for improving the fatigue performance of existing welded steel and steel-concrete composite structures such as highway bridges. The fatigue resistance of treated joints is enhanced by improving the geometry of the weld toe, and introducing compressive residual stresses. However, a lack of tools for quality assurance has slowed UIT's adoption by bridge authorities. The current study was undertaken to examine the fatigue performance of structural steel welds subjected to UIT at various levels, including intentional under-treatment and over-treatment, and to relate the fatigue performance of the treated welds to geometric and metallurgical properties measured to control the treatment quality. The last objective was to use the laboratory results to develop acceptance criteria for the quality control of UIT in bridge applications. Fatigue tests of non-load carrying fillet welded attachments were conducted on properly treated, under-treated, and over-treated weld toes. Statistical analyses of the fatigue life data were performed and crack growth was monitored using the alternating current potential drop (ACPD) method. Measurement of local properties (such as weld toe geometry, local hardness, and residual stresses) and examination of the weld toe microstructure were also performed on the untreated and treated welds. The effects of weld toe geometry on the local stresses in the untreated and treated welds were also investigated using elastic finite element analysis (FEA) to obtain the stress concentration factor (SCF) for the different treatment cases and to examine the changes in the SCF for the different weld toe geometries. Based on the statistical analysis performed in this research, the results illustrated that UIT significantly improved the fatigue lives of weld details regardless of the investigated level of treatment quality. The fatigue lives of welded details under constant amplitude (CA) loading and constant amplitude loading with under-loads (CA-UL) were increased up to 30 and 27 times respectively. On average, the fatigue life of the treated weld details was slightly lower under CA-UL than under CA loading. Treatment quality had little impact on the mean of the S-N curves. However, it did impact the design (95% survival probability) S-N curves, with the curve associated with a proper treatment slightly higher than the curves for poor or unknown treatment quality. Local near-surface microhardness and compressive residual stresses were greatest for the over-treated welded details, followed by the properly treated and then the under-treated welded details. Increasing the treatment speed resulted in a greater reduction in the surface microhardness and compressive residual stresses than decreasing the treatment intensity. Finite element analyses showed that changes in weld toe geometry due to UIT can cause a decrease in the SCF near the surface of the treated weld toe. The SCF was the lowest for the properly treated steel specimens and slightly higher for the under-treated specimens. For the over-treated specimens, the SCFs were nearly as high as for the untreated weld. The SCF increases as the thickness of the flange increased up to 19 mm. With further flange thickness increase to 38 mm, the SCF did not change substantially. The work presented herein demonstrated that indent depth measurements from the base metal side, commonly used for quality control, may not identify over-treatment on their own. Indent depth measurements from both the weld and the base metal sides, obtained by measurement of weld toe impressions, offer a good alternative means for identifying over-treatment. However, for identifying under-treatment, indent depth measurements should be used in conjunction with visual inspection for traces of the original weld toe.

Download or read book Development of Equipment Parameter Tolerances for the Ultrasonic Inspection of Steel Components written by and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Signal Processing Handbook written by Stergios Stergiopoulos and published by CRC Press. This book was released on 2017-09-08 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in digital signal processing algorithms and computer technology have combined to produce real-time systems with capabilities far beyond those of just few years ago. Nonlinear, adaptive methods for signal processing have emerged to provide better array gain performance, however, they lack the robustness of conventional algorithms. The challenge remains to develop a concept that exploits the advantages of both-a scheme that integrates these methods in practical, real-time systems. The Advanced Signal Processing Handbook helps you meet that challenge. Beyond offering an outstanding introduction to the principles and applications of advanced signal processing, it develops a generic processing structure that takes advantage of the similarities that exist among radar, sonar, and medical imaging systems and integrates conventional and nonlinear processing schemes.

Download or read book Structural Materials Technology written by Sreenivas Alampalli and published by CRC Press. This book was released on 2000-02-29 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fourth Structural Materials Technology NDT Conference was held in Atlantic City, New Jersey, with over sixty speakers presenting on a wide variety of topics. The goal of this conference was to inform engineers and researchers of the new nondestructive testing/nondestructive evaluation (NDT/NDE) technologies and techniques available for use in transportation construction. The use of alternative materials is challenging NDT/NDE professionals to develop new methods or modify existing techniques to address quality control, quality assurance, and long-term monitoring of structures built or strengthened with these materials. One such alternative is fiber-reinforced polymer (FRP) products. This conference included papers on this topic and a panel discussion that focused on the future of NDT/NDE technologies for structures built or rehabilitated with FRP composites. These proceedings contain the 62 papers that were presented at the conference, arranged according to session number. An author index is included.

Download or read book Inspection and Management of Bridges with Fracture critical Details written by Robert J. Conner and published by Transportation Research Board. This book was released on 2005 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 354: Inspection and Management of Bridges with Fracture-Critical Details explores the inspection and maintenance of bridges with fracture-critical members (FCMs), as defined in the American Association of State Highway and Transportation Officials' Load and Resistance Factor Design (LRFD) Bridge Design Specifications. The report identifies gaps in literature related to the subject; determines practices and problems with how bridge owners define, identify, document, inspect, and manage bridges with fracture-critical details; and identifies specific research needs. Among the areas examined in the report are inspection frequencies and procedures; methods for calculating remaining fatigue life; qualification, availability, and training of inspectors; cost of inspection programs; instances where inspection programs prevented failures; retrofit techniques; fabrication methods and inspections; and experience with fracture-critical members fractures and problems details.

Download or read book Structural Materials Technology written by and published by . This book was released on 1996 with total page 424 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 1999 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review of Progress in Quantitative Nondestructive Evaluation written by Donald O. Thompson and published by . This book was released on 1982 with total page 1176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guidelines for Evaluating Corrosion Effects in Existing Steel Bridges written by and published by Transportation Research Board National Research. This book was released on 1990 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: