Increased Damping in Cantilevered Traffic Signal Structures

Hamilton, H. R.; Riggs, G. S.; Puckett, Jay A.

doi:10.1061/(asce)0733-9445(2000)126:4(530)

Cited by 34 publications

(13 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Truck-induced wind gusts are the result of large vehicles passing beneath the signal support structures. Hamilton et al (6) found that natural and truck-induced wind gusts may be major contributors to out-of-plane mast arm vibrations, a finding supported by Cook et al (10). Albert et al (11) determined that overall natural wind gusts produce a larger response in cantilevered traffic signal structures than gusts produced by trucks passing beneath the signals, a conclusion consistent with findings by Hartnagel and Barker (12) and Chen et al (13).…”

mentioning

confidence: 55%

“…tube thin-walled circular members with little inherent damping. A measure of the inherent damping in a system, or the ability to dissipate energy, is the critical damping ratio (5), which has been measured to be between 0.15% to 0.5% (6) in traffic signal support structures. Low damping can result in a dynamic response that is many times larger than the static response caused by the same load.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Reducing Fatigue in Wind-Excited Support Structures of Traffic Signals with Innovative Vibration Absorber

Christenson

Hoque

2011

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

Support structures of traffic signals are flexible, lightly damped structures that are highly susceptible to wind-induced vibration. The sustained large-amplitude deflections caused by these dynamic vibrations can result in fatigue cracking and failure. The proposed innovative vibration absorber reduces fatigue in support structures of traffic signals with the use of the mass of the signal head as a damped-vibration absorber. This novel concept, referred to as a signal head vibration absorber (SHVA), provides energy absorption in the form of increased damping to the lightly damped signal support structure. A prototype smart vibration absorber, envisioned as an inexpensive retrofit to signal support structures that were experiencing excessive wind-induced vibration, was tested in a full-scale laboratory experiment at the University of Connecticut. The SHVA was experimentally shown to have increased the damping in the signal support structure from 0.2% of the critical damping ratio to 10.1%. For steady state vibration, this difference is equivalent to a 98.3% reduction in the response and virtually eliminates any deflections. A single SHVA can be applied to a wide range of signal support structures while still achieving reasonable performance. The SHVA can change the way vibration in traffic signal support structures is mitigated.

show abstract

mentioning

confidence: 55%

mentioning

confidence: 99%

Reducing Fatigue in Wind-Excited Support Structures of Traffic Signals with Innovative Vibration Absorber

Christenson

Hoque

2011

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

show abstract

“…Galloping is most likely the primary cause of excessive vibrations in these types of structures. Hamilton et al [9] hypothesize that due to the overall interaction of the entire mast arm structure, galloping may also initiate horizontal motion.…”

Section: Fatigue D E Sig N T Esting and M Odelingmentioning

confidence: 99%

Crashworthiness of Traffic Light Steel Poles in Vehicle Collisions

Siriya¹

2021

Preprint

View full text Add to dashboard Cite

Vehicle crashworthiness focuses on the capability of a vehicle to protect its occupants in a collision. The Canadian Highway Bridge Design Code [2] does not provide design criteria for vehicle occupant safety except by field testing. The test-guided product development process is very costly and time-consuming. As an alternative, computer simulation tools are increasingly being used. The aim of this research is to contribute to the efficient design of traffic light poles by developing an experimentally calibrated, computer-based, finite-element model using LSDYNA [54], capable of predicting accurately their response when subjected to vehicle impact. The case of steel pole embedded directly in soil was proved to be strong enough to offer protection under service loading and vehicle impact. Side impact crashed proved to be more severe for the vehicle occupant as a result of the weak structural performance of the side doors of the vehicle. Based on this an innovative pole supported on a hard rubber base is introduced to improve crashworthiness.

show abstract

“…Various mitigation devices have been proposed for traffic signal support structures with varying degrees of complexity and performance (4,(10)(11)(12). Hamilton et al conducted extensive studies of different types of vibration absorbers attached to a 50-ft (15.24-m) mast arm (12). Free vibration tests were conducted, and acceleration measurements at the tip of the mast arm were used to determine the critical damping ratio of the traffic signal structure.…”

mentioning

confidence: 99%

“…This damper was relatively complex and had a high manufacturing cost. Hamilton et al also considered a dual strut configuration that required a strut to be placed at an angle between the mast arm and the pole (12). The strut was found to increase the critical damping ratio to 6.00%.…”

mentioning

confidence: 99%

Field Testing of Signal Head Vibration Absorber to Reduce Fatigue in Wind-Excited Traffic Signal Support Structures

Christenson

Cashany

Hua

et al. 2014

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

The signal head vibration absorber (SHVA) is an effective vibration mitigation device proposed to reduce the in-plane wind-induced vibration and corresponding fatigue of traffic signal support structures. An SHVA was successfully tested in the Advanced Hazards Mitigation Laboratory at the University of Connecticut by being subjected to both free and force vibration testing with pluck tests and a linear shaker. A new SHVA design has been developed; it requires no modifications of standard signal heads or mounting hardware and is readily installable in the field for both retrofit and new applications. This paper provides research verification of the ability of an SHVA to reduce wind-induced vibration in traffic signal support structures. Successful field testing of a traffic signal support structure with a mast arm 60 ft (18.29 m) long was conducted at Texas Tech University's National Wind Institute Wind Engineering Research Field Laboratory. The field test results, consistent with prior laboratory testing, showed that the SHVA was able to reduce in-plane motion of the mast arm tip by 90%.

show abstract

Increased Damping in Cantilevered Traffic Signal Structures

Cited by 34 publications

References 6 publications

Reducing Fatigue in Wind-Excited Support Structures of Traffic Signals with Innovative Vibration Absorber

Reducing Fatigue in Wind-Excited Support Structures of Traffic Signals with Innovative Vibration Absorber

Crashworthiness of Traffic Light Steel Poles in Vehicle Collisions

Field Testing of Signal Head Vibration Absorber to Reduce Fatigue in Wind-Excited Traffic Signal Support Structures

Contact Info

Product

Resources

About