The issue of weld fatigue has been an issue for manufacturers since the beginning of the age of industrialization, and while technology has advanced greatly in recent decades, welding fatigue continues to be the most common failure mode, particularly in frames for mobile equipment such as trailers. Currently, There are no federal regulations as to how a trailer is to be designed with regard to welding. Furthermore, most mechanical engineering programs include little to no discussion on the general topic of fatigue, and typically contain no discussion at all of welding fatigue.
Combine this lack of education and mandated practice with what T.R. Gurney noted in his book Fatigue of Welded Structures that about 90% of all failures in engineering components are due to fatigue. This is especially pertinent to trailer manufacturers as weld fatigue is a common failure mode for structures that are subject to fluctuating stress. Because trailers are used to haul anything and everything, they experience unpredictable dynamic loading and a large magnitude of loads resulting in higher rates of fatigue failures.
With millions of American using the roadways every day, safety is of paramount importance. But fatigue related failures happen suddenly and often lead to catastrophic results. Imagine a fatigue failure on a trailer hauling heavy equipment in the middle of a packed highway or on a dark road in the middle of the night. Although all fatigue cannot be avoided, and manufacturers often warn users to physically inspect their trailers on a regular basis for signs of fatigue, much can be done to prevent or minimize such failure in the design stages. But without educational resources in mechanical engineering courses and a shortage of engineers, where does one go to learn more about this issue? What type of fatigue failures are common and what do you do to minimize the risk of such a failure? These are all relevant questions that need answered.
NATM is offering a workshop at the 27th Annual Convention and Trade Show in New Orleans, La. Feb. 11-13th, led by Duane K. Miller, Sc. D., P.E. of Lincoln Electric to discuss this very issue, “Fatigue of Welding Connections” and “Listen to the Steel: Learning from Failures”. Dr. Miller is a three-time recipient of the American Welding Society’s Silver Quill Award and in 2001 received the American Institute of Steel Construction’s T.R. Higgins Lectureship Award. For more information on this opportunity please email [email protected].