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 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Order to determine equivalent static pressures for fatigue loads on cantilevered highway support structures a cantilevered Variable Message Sign(VMS) located along Interstate westbound at mile marker 48.5 in northern New Jersey was continuously monitored for three months. The structure was instrumented with strain gages, pressure transducers, and a wind sentry. All the data was collected with a Campbell Scientific CR9000 digital data acquisition system. A cellular phone transceiver enabled remote communication with the data logger. The system and instrumentation was powered with solar powers and marine batteries. Short-term testing was performed on the structure to determine the dynamic characteristics such as stiffness, natural frequency, and percent of critical damping. Results of the short-term test indicated that the stiffness was 0.24 kN/mm, the first and the second modes were 0.87 cycles/s and 1.22 cycles/s respectively, and the percent of critical damping for the first and second modes were 0.57 percent and 0.25 percent respectively. Long-Term monitoring was performed to capture the structures response to natural wind gusts, galloping, and truck-induced wind gusts. This data would then be used to determine appropriate fatigue design wind loads for future sign support structures. During the three months of monitoring the structure did not experience galloping, which is a phenomena highly dependent on location. A galloping design pressure of 1000 Pa was recommended based on previous research. The summer months, which is when the structure was monitored, were not conductive to the strongest natural winds patterns in Northern New Jersey. The highest natural wind speed that was recorded was 7.5m/s. It is believed that much stronger winds are present in winter and spring, therefore a natural wind gust design pressure of 250 Pa was recommended. Truck-induced gusts were measured and a linear gradient for the truckinduced gust design pressure was determined. The truck-induced gust design pressure ranged linearly from 1760 Pa at 0 to 6m above the surface of the road to 0 Pa at 10.1m and over.

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 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 Fatigue Performance of Variable Message Sign Luminaire Support Structures Fatigue testing and failure analysis of aluminum luminaire support structures written by Gary R. Consolazio and published by . This book was released on 1998 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Concept Development of a Bullnose Guardrail System for Median Applications written by Bob W. Bielenberg and published by . This book was released on 1998 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research study consisted of the design, fabrication, and full-scale vehicle crash testing of a bullnose barrier concept for the end treatment of median hazards. The bullnose concept consisted of a 12-gauge thrie beam rail supported by twenty-two wood posts, eleven posts on each side of the system. Horizontal slots were cut in the valleys of selected thrie beam sections to aid in vehicle capture as well as to reduce the buckling and bending capacities of the rail. Two full-scale crash tests were performed, the first using a 2000-kg pickup truck and the second using an 820-kg small car. The first test, impacting at a speed of 101.4 km/h and an angle of 0.1 degrees at a 1/4-point offset, was unsuccessful. Although the vehicle showed no potential for vehicle override, the thrie beam ruptured causing uncontrolled penetration of the vehicle behind the barrier. Consequently, the bullnose system was modified to include additional breakaway posts and horizontal slots in other thrie beam sections. The second test, impacting at a speed of 103.3 km/h and an angle of 3.4 degrees was determined to be successful according to the safety standards set forth by the Test Level 3 evaluation criteria described in the National Cooperative Highway Research Program (NCHRP) Report No. 350, "Recommended Procedures for the Safety Performance Evaluation of Highway Features". The data and information gathered from the development phase of this project will be used in the development of a computer simulation LS-DYNA model of the bullnose system as well as an improved bullnose guardrail design

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 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 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 Risks in the Connections of Sign Support Structures written by and published by . This book was released on 2008 with total page 216 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 Strength and Evaluation of Sign Structures Volume 1 written by Xuejun Li and published by . This book was released on 2006-06-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cost effective Connection Details for Highway Sign Luminaire and Traffic Signal Structures written by and published by . This book was released on 2011 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents the results of a comprehensive experimental and analytical study that evaluated fatigue performance of several critical welded connections in the highway sign, signal and high-level luminaire support structures. In this study, infinite life fatigue resistance of connection details in the existing inventory was established and new cost-effective fatigue resistant connections were developed. About 80 full size galvanized specimens of sign, signal and high-level luminaire support structures containing different welded connections were fatigue tested.

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 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 Initial Analytical Investigation of Overhead Sign Trusses with Respect to Remaining Fatigue Life and Predictive Methods for Inspection written by Husam Aldeen Alshareef and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most state highway agencies do not perform routine fatigue inspections on highway signs, luminaires, and traffic signals, thereby increasing the potential for unnoticed fatigue cracking. The Kansas Highway System utilizes over 450 sign trusses, most of which have been in service for 30-45 years. In addition to aging support structures, the structural designs of these signs and signals sometimes result in significant cyclical loading due to wind gusts. This study conducted fatigue evaluations using nominal axial member-specific stress ranges corresponding to a wind speed database for a 45-year period, as well as hundreds of structural analysis simulations. Potential fatigue failure was assessed for each member of the support structure by evaluating the ratio of consumed fatigue cycles to ultimate fatigue cycles using Miner's rule to estimate finite life. If the ratio was close to zero after 45 years or any number of actual service years, the member was expected to have a practically infinite life. If the ratio was close to 1 after the service years, the member was expected to be at the end of its life. This information can help inspectors identify for critical spots that may have developed fatigue cracks that otherwise would be difficult to detect. Two approaches were hypothesized to account for fatigue life deterministically and probabilistically. Fatigue Life Simulator Software (FLSS) was developed to manage hundreds of simulations and determine the fatigue life of all members in a structure in specific areas of Kansas. FLSS is compatible and works simultaneously with STAAD. Pro software and Sign Truss Interface provided by KDOT to generate results. Users apply the results to study the behavior of overhead structures and identify critical spots that should be physically inspected and potentially replaced. Results in Kansas indicated a range of structural fatigue life varying by city. Modifications were made to the output files of Sign Truss Interface to incorporate American Association of State Highway and Transportation Officials (AASHTO) load cases 1 and 2 and simulate wind speed into wind pressure using the effect of the two load cases. The modification also automatically incorporated 45 years' worth of wind speed data into the Sign Truss Interface to simulate and generate structural models to determine corresponding stresses to the wind effect.