Study of the Effects of Wind Power To Establish Fatigue Design Criteria for High-Mast Poles

Traffic signal poles and high-mast poles are used by transportation agencies to control and illuminate intersections; their structural design is governed by national specifications. High-mast poles are lights located around highway interchanges that range from 80 to 140 feet in height. Unfortunately, these flexible structures are susceptible to vibration from wind leading to fatigue cracking near the welds. Because of the nature of failure in some areas of the country, recent changes to the requirements have called for expensive member size increases. However, for the areas that in the past had no problems with failures, such increases may be unnecessary and uneconomical. In a previous study conducted by the University of Wyoming, fatigue cracking of traffic signal poles was determined to be directly related to the average wind speed. Recommendations of changes to the requirements of lower wind areas were made for the traffic signal poles. However, high-mast data did not indicate the same behavior. The goal of this research is to gain a more complete understanding of the relation between wind speed and high-mast pole cracking through the collection of more data. This research project will further analyze the data collected through a cracked and non-cracked categorization taking into account th