Field testing of signal head vibration absorber to reduce fatigue in wind-excited traffic signal support structures

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%.