Experimental study of a ball-pendulum and beam system under random and deterministic excitation with an application to traffic signal support structures
MetadataShow full item record
In recent years, among 36 states, approximately one half of them had problems with the flow induced vibrations of cantilevered support structures. Generally, the vibrations occurring were reported to be in the in plane of the structure (vertical-plane vibrations of the mast arm) in a direction which is normal to the direction of the wind flow. As a result of these high amplitude vibrations, some of the signal structures failed and collapsed due to fatigue. Many engineering structures besides traffic signal lights are subjected to vibrations which are mostly random in general. These systems may also fail due to fatigue resulting from high amplitude vibrations. In this research, an autoparamertic damper was introduced. The energy dissipation from the beam to the pendulum was observed. A new methodology for locating the position of the ball was also introduced. In this method, infrared diodes were used to determine the position of the ball. The ball itself behaves as the intermpter of the light beam. When the light beam is intermpted, the output shows a peak and these peaks are the points where the ball stays at that instance. In the lab, random and deterministic experiments were conducted. Both of these tests gave insight about the dynamic characteristic of the damper. The damper will be tested also in the traffic signal stmcture located at the Texas Tech University Wind Engineering Research Field Laboratory (WEFLR). This study mainly investigates the potential of a novel absorber with an application to the traffic signal structure.