HILL AIR FORCE BASE, UT – An agreement 25 years in the making was signed June 13 at Hill Air Force Base as University of Utah officials and the Ogden Air Logistics Center Engineering Directorate leadership and staff gathered at a conference room at the base.

Angie Tymofichuk, director of the OO-ALC Engineering Directorate, took pen in hand and added her signature to an Educational Partnership Agreement alongside the signature of Tim Ameel, Mechanical Engineering Department chairman at the U of U.

“It’s been a long time coming,” said Ameel, afterward as he recalled efforts begun earlier by David Hoeppner, professor of mechanical engineering at the U of U. “He started this process when he was department chairman 25 years ago,” said Ameel.

Hoepnner was present and voiced his own excitement at the gathering as the document was signed.

Leadership changes at Hill over the course of the 25 year time period brought its own challenges to the process during that period as interest waxed and waned, said Ameel.

Leadership from both sides concurred that this signed agreement now makes it much easier for joint research and development work by mechanical engineering students at the U of U in conjunction with the base. Such projects had occurred ad hoc but meant lots of paperwork and lots of approvals bogged down the process.

“It’s a great win-win because it’s good for the university — it gets them real world exposure — and it’s great for us because we can take our really top issues and get research, fairly inexpensive research, applied to our top issues,” said Roger Beal, of the OO-ALC Engineering Directorate.

While the base does not pay for the research to be conducted, base resources can be used, such as machinery and testing equipment, to aid the researchers as they conduct data testing for master’s and doctorate thesis work.

“Research is not an inexpensive endeavor,” said Craig Shaw, who manages the OO-ALC Engineering Directorate’s Office of Research and Technology Agreements. “This is all going to help, along with every other area of science and engineering, on the center,” he said.

This step paves the way for other departments at the U of U, and eventually other schools, to expand their own research and teaching applications. Beal and others have indicated an interest on the part of Hill as they look to the future to get others on board.

Indeed, U of U representative Ameel indicated that he regards this as not just a milestone but an avenue to more achievement. “I think it’s the starting place — it’s not just the ending place — to a new relationship between the University of Utah and Hill. We’re the first department to make this agreement, or to sign the EPA, and now the Electrical Engineering Department and others are looking into the possibility — and so it’s really going to help the entire engineering community at Hill and give us some really interesting problems to work on.

“We’d like to see other folks get involved and again provide what’s needed to be able to improve the services that people up here are providing to the Hill community and the Air Force,” Ameel said.

One such project

This agreement paves the way for upper level graduate students to do research with the base and work on state-of-the-art problems which the Air Force and the base have before them.
The challenges involved in maintaining the A-10 weapon system are currently on the minds of Jacob Warner, a Science, Mathematics, Research and Research for Transformation (SMART) Air Force civilian employee, and Dallen Andrew, a Palace Acquire (PAQ) Air Force civilian employee, who are both currently attending the University of Utah studying mechanical engineering and work in the A-10 System Program Office. The two students are currently working on their master’s theses doing fatigue experiments with aluminum “coupons,” 4 inches wide by 16 inches long, on a 55,000 pound Instrom load-frame at Hill AFB 809th Maintenance Support Squadron Science and Engineering Laboratory. Their theses involve taking experimental coupons that have holes drilled either in the center (for one project) or near the edge (for the other project), having a small notch placed at the hole and subjecting the coupons to fatigue loading. They cold work the coupons with a crack in the hole, then record and document crack growth behavior.

Cold working is the process of pulling a tapered mandrel or rod through a hole which is slightly smaller than the mandrel. This plastically deforms the hole and results in a compressive residual stress around the hole which extends the fatigue life of the component, or in other words — potentially slows down or stops any crack growth.

Fatigue testing involves the use of a load frame that cylically loads the coupon. This replicates what occurs during years of actual aircraft usage.

What they’re trying to prove

Their hypothesis is that the cold working of a hole that was cracked prior to cold working will provide a significant increase in fatigue life compared to an identical hole that was not cold worked. Fastener holes represent one of the most common fatigue details found in air frame structures. When a crack indication is found at a hole, current U.S. Air Force technical data requires that the hole must be oversized to a larger diameter to remove the damage. Unnecessarily oversizing a hole is undesirable from a fatigue point of view. This research has the potential benefit of not requiring the hole to be oversized and potentially could reduce the number of inspections required for aircraft. This would increase aircraft availability to the war-fighter and provide more support to those in uniform.

After performing some fatigue testing himself, Andrew said it enhances his understanding of the analytical work he does as an A-10 aerospace engineer. Both he and Warner work on base in the A-10 Aircraft Structural Integrity Program (ASIP) office as aerospace engineers and wanted to expand their knowledge by attending the University of Utah in the mechanical engineering master’s degree program.

Andrew said, “I had no fatigue or fracture mechanics knowledge when I graduated from college. I worked in the ASIP office for a year before going back to school, and I gained a lot of work experience. Now I can see I have benefits from seeing it in a real work environment plus getting education in the theory and background of what I do at work every day, and it is an awesome thing.”

Practical applications

Both highly recommend their major and encourage others to make practical applications part of their own educations.

“This EPA will allow us to have more resources available to us, both on the University of Utah Department of Mechanical Engineering side and on the Air Force side,” said Warner.

“As time goes on, it will help many other U of U students and Air Force employees gain technical education and experience. The EPA will facilitate projects like ours in the future.”

View the original story at the Hilltop Times. Article by Mary Lou Gorny, photograph by Alex Lloyd.