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

Abstract

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%.

A Framework for Vibration Attenuation in Traffic Mast Arm Structures under Wind Loads

“…The studied traffic signal has a mast arm length of 18.3 m (Fig. 2) [21]. The tapered pole (5.97 m high and 0.55 m average diameter) is mono-tubular, and the cantilevered arm has a rounded section.…”

“…Magnetic dampers placed in the traffic signal head can yield significant vibration reduction [20]. Field results suggest that the signal head device is effective [21].…”

Numerical Simulation Study of Vibration Characteristics of Cantilever Traffic Signal Support Structure under Wind Environment

“…Hong et al [1] evaluated the statistics of the stress range and the fatigue reliability of the structure under the action of natural wind gusts for some support structures suitable to be represented by simplified structures. Christenson et al [2] proposed the signal head vibration absorber (SHVA) to verify the ability to reduce wind-induced vibration in traffic signal support structures. Wieghaus et al [3] proposed a low-cost damage avoidance approach to mitigate the fatigue effects of wind on cantilevered traffic signal support structures.…”