Aeolian Vibration Test:

The purpose of this testing is to demonstrate that the conductor accessories will protect the conductor when it is subjected to dynamic, wind induced bending stresses. It is well understood in the industry that conductors strung under tension will vibrate in standing waves when subjected to laminar wind flows in 4.5m/s according to IEEE 1138 for OPGW and 16.1km/h (4.47m/s) according to IEEE 1222 for ADSS. Within the span itself, this vibration activity has little or no influence on the conductor. However, at the structures where the conductors are supported or dead-ended, this vibration activity produces bending stresses. The peak-to-peak amplitude of the vibration of the conductor in the span is generally less than the diameter of the conductor itself, but over a number of years, if not properly protected, the conductor can experience fatigue failures.

The laboratory test arrangement for the aeolian vibration testing of the conductor suspension assembly consisted of a 30 meter span of conductor with a dead-end assembly applied to each end, and a suspension assembly applied to the center of the span and secured to a rigid tower. During the test, the tension in the conductor was maintained at 25% RTS for OPGW (100% MIT for ADSS). using a tension beam/weight basket. A vibration shaker was used to initiate and maintain a vibration at a frequency of (830/Diameter of conductor in mm) hertz for a period of 100 million cycles. Visual Observations were made daily of the conductor and the Dead-End and suspension assemblies objective.

Observations

• to verify the mechanical integrity of the cable and the supporting hardware when subjected to simulated vibration conditions
• to verify the optical performance of the cable when subjected to the specified vibration conditions