Each year, cities across the United States, including Lubbock, spend thousands of dollars replacing traffic signals and street signs. Often the damage to these structures comes from wind, even the draft created by passing trucks.
The wind tunnel at Texas Tech University could help reduce the amount of money cities spend each year replacing wind-damaged street signs. Researchers hope to develop an improved mounting technique for the signs and traffic signal lights, specifically the arms they are mounted on. The wind causes the arms to bounce up and down, sometimes so violently, they can crack. The steel arms could eventually open up and cause the arm to crash to the street below.
"All you need is fairly steady winds, not particularly fast. You see it at lighter winds, around 30 mph and the motion can go on all day because once it gets started, there is no mechanism to stop it," says Chris Letchford a Texas Tech Civil Engineering professor.
To research this phenomenon, researchers installed a series of test traffic lights outfitted with special monitoring devices. "We can actually plot the motion of the end of the arm whether up and down, or circular, or ellipse or whatever, and then we have an anemometer on top of the mast so we can record the components of the wind speed and the motion of the arm," says Letchford.
Researchers are hoping to use this information to create a design standard for the poles and mounting brackets that will be more economical for cities.
The Texas Tech Wind Science and Engineering Research Center is also working with the University of Texas at Austin on this research. UT students and professors are looking at using different materials that would more easily resist fatigue.