Download or read book Fatigue Performance of Full span Sign Support Structures Considering Truck induced Gust and Natural Wind Pressures written by Scott Ginal and published by . This book was released on 2003 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Risks in the Connections of Sign Support Structures written by and published by . This book was released on 2008 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Performance of Variable Message Sign Luminaire Support Structures Fatigue related wind loads on highway support structures written by Gary R. Consolazio and published by . This book was released on 1998 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes research which focused on determining equivalent static pressures for fatigue loads on cantilevered highway sign support structures. A cantilevered variable message sign (VMS) instrumented with strain gages, pressure transducers, and a wind sentry, was continuously monitored for three months. Short-term testing was conducted on the structure in order to determine the dynamic characteristics such as stiffness, natural frequency, and percent of critical damping. Long-term monitoring was performed to capture the structure's response to natural wind gusts, galloping, and truck-induced wind gusts.

Download or read book Structural Analysis of Sign Bridge Structures and Luminaire Supports written by and published by . This book was released on 2004 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Performance of Variable Message Sign Luminaire Support Structures written by Gary R. Consolazio and published by . This book was released on 1998 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bridge Engineering written by and published by BoD – Books on Demand. This book was released on 2024-07-17 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world’s aging infrastructure faces unprecedented challenges. Bridges, the vital lifelines of the transportation network, are in need of innovative solutions to combat the effects of increased traffic loads, environmental stress, and the passage of time. This edited volume equips you with the knowledge to design and maintain safer, more durable, and sustainable bridges for the future. Explore advancements in the following aspects of bridge engineering: •Material science: Discover strategies to enhance the longevity of concrete bridges, and explore the potential of next-generation materials. •Fatigue assessment: Learn cutting-edge analytical methods to identify and address fatigue damage in critical bridge components, ensuring public safety and efficient maintenance. •Robotic and automation technologies: Uncover how robotics and automation are revolutionizing bridge repair and maintenance, streamlining processes and optimizing resource allocation. •Structural health monitoring (SHM): Delve into the exciting world of the Internet of Things (IoT) and its application in bridge health monitoring. Learn how wireless sensor networks can provide real-time data for proactive maintenance and informed decision-making. This book is a valuable resource for: •Bridge engineers seeking the latest advancements in design, materials, and monitoring techniques. •Policymakers developing sustainable infrastructure strategies. •Researchers pushing the boundaries of bridge engineering through innovative materials and methods. •Students eager to understand the future of bridge design and construction. Embrace the future of bridge engineering. Ensure a safer and more sustainable tomorrow.

Download or read book Field Testing of Cantilevered Traffic Signal Structures Under Truck induced Gust Loads written by and published by . This book was released on 2007 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue resistant Design of Cantilevered Signal Sign and Light Supports written by Mark R. Kaczinski and published by Transportation Research Board. This book was released on 1998 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue resistant Design of Cantilevered Signal Sign and Light Supports written by Robert Joseph Dexter and published by Transportation Research Board. This book was released on 2002 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Related Wind Loads on Highway Support Structures written by Kevin W. Johns and published by . This book was released on 1998 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vehicle induced Gust Loads on Aluminum Overhead Sign Structures written by Joseph B. Zell and published by . This book was released on 1977 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mitigating Fatigue of Cantilevered Overhead Sign Structures Due to Natural and Truck induced Wind Gusts written by Mohamed Salah Gallow and published by . This book was released on 2014 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cantilevered overhead sign structures (COSS) are widely used across highways in the U.S. Several cases of failures have been reported for such structures due to fatigue wind loads. The structure's dynamic characteristics such as natural frequency and critical damping are responsible for its behavior during those loads. When the frequency of wind gusts load matches the fundamental frequency of the OSS, resonance occurs, which causes excessive vibrations. Consequently, fatigue stresses in crease and may exceed the fatigue critical limit, resulting in failure. Vibrations and fatigue stresses amplitudes are dependent on the structure's natural frequency. The objective of this study is investigating natural frequencies of COSS in order to mitigate fatigue stresses due to natural and truck-induced wind gusts. Investigating damping and other fatiguee wind loads are out of the scope in this study. Alterations in factors such as the members' configuration, arrangement, sizes, and layout of the structure control its stiffness and mass distribution which controls its natural frequency and consequently, fatigue stresses. A parametric study was considered in order to investigate the effect of these factors and recommend the best layout between 4-chord, 2-chord, and monotube CSS in mitigating fatigue. Structures were designed according to the American Association of State Highway and Transportation Officials (AASHTO) 2013, Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals (mentioned hereafter as the AASHTO Support Specifications (2013)) and modeled using commercial finite element analysis software. Wind pressure power spectral density and time history loading functions were applied on these structures to simulate natural and truck-induced wind gusts, respectively. Eventally, on the contrary of the 2-chord structure, slanted monotube CSS with curved end post was found to have least mass, highest frequency and nearly smallest fatigue stresses.

Download or read book Engineering Journal written by and published by . This book was released on 2007 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Calibration of Fatigue Design Wind Pressure for Sign Luminaire and Traffic Signal Support written by Guigui Zu and published by . This book was released on 2013 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study is focused on calibration of fatigue design wind pressure for sign, luminaire and traffic signal support under natural and truck-induced wind gusts. The design of the support structures in Canada is governed by the current Canadian Highway Bridge Design Code (CHBDC). However, the code is not specific on the fatigue design wind pressure (natural or truck-induced) for these structures. Although there are equivalent static natural and truck-induced wind pressures for fatigue design recommended in the provisions of the American Association of State Highway and Transportation Officials (AASHTO), none of relevant studies discussed the implied reliability by using these design pressures based on Canadian practice. Code calibration analyses of the sign, luminaire and traffic signal support under natural and truck-induced wind gusts were carried out in the study. For the calibration, the support structures were approximated by a linear elastic single-degree-of-freedom (SDOF) system, structural response with selected natural frequencies, damping ratios under natural and truck-induced wind gusts was estimated. A target reliability index of 4.25 for a service period of 75 years was adopted for the calibration. The calibration results were used to recommend fatigue design wind pressure for sign, luminaire and traffic signal support under both natural and truck-induced wind gusts. The recommended values could be directly adopted by the CHBDC.

Download or read book Analytical Investigation of Saddle Connections for Overhead Sign Trusses with Respect to Strength and Fatigue Performance written by Danqing Yu and published by . This book was released on 2021 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge-type overhead truss sign structures (OHTSS) are widely used over active highways across the United States. An OHTSS is comprised of a 3D truss and two support frames at each end. The structures are usually made of steel or aluminum. Many state DOTs use their own types of connections that are not documented in specifications. Since 2015, the Kansas Department of Transportation (KDOT) has used a type of 'saddle connection' at the joints of truss chords and support frame pipes. Wind loads are the primary type of load a sign structure resists besides the gravity load. Since wind loads are periodic, fatigue properties are important in the design of OHTSS. As a newly developed connection, KDOT sought information regarding the mechanical performance of the saddle connection. Studies were needed to verify the safety of the connections, particularly regarding its fatigue susceptibility. This report presents a study mainly aimed at evaluating the fatigue susceptibility of the saddle connections using finite element analysis (FEA). The study consisted of the following four parts: Part 1: Global behavior analysis: an analysis aimed at determining the global behavior of the structures and the location of critical connections. Linear-elastic material properties were used. Part 2: Structural Hot Spot Stress analysis: an analysis was performed to determine structural Hot Spot Stresses along each weld in the critical connections identified in Part 1. Linear-elastic material properties were used. Part 3: Effective notch stress analysis: a linear-elastic analysis using the effective notch stress method to evaluate three welds identified to have larger stresses in Part 2. Linear-elastic material properties were used. Part 4: Extreme loading analysis: An analysis to evaluate the behavior of the saddle connections and the overall structures under extreme loading and provide comments regarding the strength-related safety of the saddle connections. Elastic-perfectly plastic material properties were used. Sign structures of four span lengths, including 60 ft, 83 ft, 110 ft, and 137 ft, were analyzed in Part 1 and Part 2. The 137-ft span structure was analyzed in Part 3 using the effective notch stress method. The 60-ft and 137-ft span structures were analyzed in Part 4. In Part 1 and Part 2, AASHTO fatigue loads, including natural wind gusts and truck-induced gusts, were applied in six load modes. They included: natural wind blowing from the back, front, and side of sign structures; and truck-induced gusts acting on the right, middle, and left 12 ft of sign trusses. In Part 3, the AASHTO fatigue load of the natural wind blowing from behind the sign structure was applied. In Part 4, the overall structures and the saddle connections were loaded until the analysis terminated. The termination of analysis was governed by loss of stiffness due to the yielding of material. The study resulted in conclusions that the natural wind in the direction facing the sign panel almost always governed the fatigue demand. The bottom saddle connections were more susceptible to fatigue damage than the top saddle connections, especially the stiffener-to-pipe weld in the bottom saddle connection. Fatigue failures of the saddle connections are not likely to occur in expected real use, but attention should be paid to the stiffener-to-pipe weld in the bottom saddle connection. The analysis of the structures under extreme loading suggests that the ultimate strength of saddle connections do not govern the strength of the overall structures.

Download or read book Structural Supports for Highway Signs Luminaires and Traffic Signals written by Fouad Hilmy Fouad and published by . This book was released on 1998 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mitigating Wind Induced Fatigue in Steel Traffic Signal Support Structures written by Kyle Thomas Wieghaus and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic signal structures undergo wind-induced vibrations that result in fatigue damage accumulation and reduced service life. Mast arms have failed and required removal while in service. A dual experimental and analytical modeling approach is taken to mitigate fatigue and fracture in steel traffic supporting structures. A full-scale prototype structure is instrumented to study natural wind response. Excitation mechanisms are identified, and response is characterized statistically by a lognormal distribution. Helical strakes are found to reduce the vortex-induced vibration of cantilevered traffic signal structures, however are not a panacea for fatigue mitigation as marginal service life gains occur in severe wind environments. A probabilistic framework is extended to assess the risk of wind-induced fatigue and estimate service life while considering uncertainties in fatigue demand and capacity. The framework is successfully demonstrated against compiled inspection records. Locations with higher prevailing winds are susceptible to wind-induced fatigue, but the prevalence of low-speed vortex-induced response is primarily responsible for the early fatigue failures in more mild environments. A low-cost damage avoidance system is proposed to mitigate fatigue and fracture in steel traffic supporting structures. Applied prestress introduces a fail-safe, supplementary load path to balance dead load moment, eradicating the detrimental tensile mean stress found in traffic signal structure connections. Field observations are made without and with the proposed system installed. The benefit of applied prestress is quantified by determining service life without and with the system based on changes in response and fatigue resistance using: (i) a code-based technique; and (ii) the proposed probabilistic framework. Fatigue performance is modeled as mean stress-dependent by modifying nominal stress-life relationships. Service life is shown to increase by an order of magnitude, regardless of wind environment. The concept shows potential to reduce the detrimental effects of non-redundancy for a variety of similar, fatigue-critical infrastructure components. The validity of simplified mean stress-dependent connection modeling is explored. A fracture mechanics-based, total life (initiation-propagation) model is used to demonstrate the detrimental effect mean stress has on tube-to-transverse base plate fatigue resistance. Using fatigue strength curves derived from total life analyses, probabilistic analyses are repeated to justify the use of simplified models. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155395