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 Field Tests and Analytical Studies of the Dynamic Behavior and the Onset of Galloping in Traffic Signal Structures written by and published by . This book was released on 2007 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guide Design Specification for Bridge Temporary Works written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 1995 with total page 91 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 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 Fatigue Loading and Design Methodology for High Mast Lighting Towers written by Robert J. Connor and published by Transportation Research Board. This book was released on 2012 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB’s National Cooperative Highway Research Program (NCHRP) Report 718: Fatigue Loading and Design Methodology for High-Mast Lighting Towers provides criteria for the fatigue design of high-mast lighting towers.

Download or read book Fatigue Testing of Stiffened Traffic Signal Structures written by John P. Peiffer and published by ProQuest. This book was released on 2009 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sixteen fatigue tests were performed on twelve cantilevered traffic signal poles to quantify the fatigue resistance of a ring-stiffened built-up box connection. Two poles sizes were tested in three configurations: in-plane, out-of-plane, and diagonal. Cyclic loading was applied to produce stress ranges of up to 16 ksi in the main member, more than six times the stress range observed during field testing. Performance test results for this connection typically plot above an AASHTO detail design stress category D. Connection bolt fatigue failures were observed and may be the limiting fatigue design feature.

Download or read book Report written by and published by . This book was released on 1964 with total page 592 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 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 Structural Supports for Highway Signs Luminaires and Traffic Signals written by Fouad H. Fouad and published by Transportation Research Board. This book was released on 2003 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind induced Vibrations of Cantilevered Traffic Signal Structures written by Narendra Pulipaka and published by . This book was released on 1995 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Field Tests and Analytical Studies of the Dynamic Behavior and the Onset of Galloping in Traffic Signal Structures written by Micah Jonathan Florea and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unpredictable fatigue failures of cantilevered mono-tube traffic signal structures in Texas and throughout the United States in recent years have created the need to study their fatigue behavior. Based on recent research, the AASHTO specification has adopted a design equation for galloping loads that is overly conservative in many cases. The Texas Department of Transportation is interested in establishing design criteria for galloping that more accurately represents galloping potential and provides a more efficient design. In this study, three signal structures in Texas were monitored for a total of 9 months to detect the magnitude of galloping forces experienced in the field. Although large amplitude displacements were measured in the field, sustained galloping did not occur. In addition to the field tests, an analytical model was developed and used to perform a parametric study for predicting the galloping potential of traffic signal structures with various properties. The analytical model suggests that modifying the aerodynamic properties of the sign and signal attachments may be the most effective way to eliminate galloping

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

Download or read book Acoustic Emission Testing and FEA of Cantilevered Traffic Signal Structures written by Peili Wang and published by . This book was released on 1999 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Damping in Cantilevered Traffic Signal Structures Under Forced Vibrations written by Patrick S. McManus and published by . This book was released on 2000 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: