Twenty-year research partnership shows no signs of fatigue

"My bike started feeling really weird, wobbly while I was riding it," Steve Daniewicz recalled. "When I got home, I realized what had happened; my axle had snapped in two. I knew just enough to realize that it was a fatigue failure and not some random act of God. That was the point when fatigue research grabbed my interest."

That was in 1980. For the next decade, Daniewicz consumed all of the textbooks, published articles and research studies he could on the subject. He was using that knowledge to complete his dissertation, extending the work of a world-renowned leader in the field, when he hit an academic roadblock.

"I had reached a point where there were a few holes in my understanding. It was a long shot, but I looked up the phone number of Jim Newman, this famous NASA researcher whose work I had been studying," Daniewicz said. "I called to see if I could ask him a few questions. I was afraid he would say he didn't have time, but he didn't do that. He was very helpful and very kind. We ended up having a fairly lengthy conversation."

"I've always tried to give as much time as possible to students," Newman said.

Daniewicz completed his education in 1991 and found work as a research engineer. Meanwhile, Newman continued his work at NASA-Langley, maintaining his reputation as one of the agency's most prolific authors. And though they kept tabs on each other through mutual acquaintances, the two men didn't cross paths again until Daniewicz joined the mechanical engineering faculty at Mississippi State.

"When Steve began teaching, I was able to sponsor him for a faculty fellowship at NASA," Newman said. "The program allows academics to work side-by-side with NASA researchers for the summer."

"I made a point to try to go work with Dr. Newman for two summer fellowships. We've been working together on fatigue research ever since," Daniewicz added.

Newman retired from NASA in 2001, but nearly 40 years of professional experience wasn't enough for the self-professed "workaholic." After leaving the space agency, he accepted a position as a professor of aerospace engineering at Mississippi State. Finally at the same institution, the two engineers were able to turn the initial $130,000 fellowship that brought their professional lives together into more than $6.5 million worth of shared research grants for projects in fatigue and fracture mechanics.

"Retirement would have been boring," Newman confessed. "I'm excited about my field. There's so much to do, so many different things to study that I could never get bored."

Daniewicz added with a laugh, "I don't know if I'll be able to maintain as much passion for my work as he has after 50 years, but maybe that's why he's achieved the level of success he has. He works like a crazy person—all hours of the day—but he always has time to talk about his work with enthusiasm."

Most of the duo's work has focused specifically on metal fatigue in aircraft—how to predict crack growth and failure rates in specific materials or situations. However, recently they have also been working to change a widely accepted testing method approved by ASTM International, the governing body for materials standards.

"We've developed a new testing technique that needs to be adopted as the industry standard, but it takes time to compile data and gather enough votes to make the change," Newman said.

He added, "For the past decade, I've been doing tests to show the flaws in the current method and finding a method that provides correct data. Meanwhile, Steve and his students have been doing analysis that supports these tests."

Newman said that getting standards changed can be difficult, but he believes that the team's diligent work will pay off, and that the support they have earned from aerospace and mechanical engineering professionals will help push the standard forward.

"By being from different disciplines, we are able to reach more people and have more of an impact when pushing to revise a standard testing method," Newman said. "It's nice to have more than one voice in the wilderness calling for change, and between our colleagues and former students, we have many supporters."

Newman will present the revised standard at a future meeting of the ASTM fatigue and fracture committee. He will then submit the revised standard to a ballot for all members. If adopted, the test method developed by the Mississippi State engineers would become the international standard for determining fatigue-crack growth properties in metallic materials.

With that project coming to an end, both researchers are ready to tackle new challenges. Newman has recently taken on new teaching duties and constantly seeks out new research opportunities, while Daniewicz accepted the position of mechanical engineering department head. But despite changes to their professional roles, neither sees an end to their partnership anywhere in the near future.