High-speed connections

High-speed connections

By University Communications
March 4, 2013

Student-athlete uses physics to compare types of softball bats

Alison Gray

Photo: Student-athlete uses physics to compare types of softball bats

Menomonie, Wis. — In her first collegiate at-bat as a freshman, Alison Gray ripped the first pitch she saw over the left field fence for a home run.

Gray, in her fourth year as a starter for the University of Wisconsin-Stout softball team, knows a little more now about why that hit went over the fence, thanks to a College of Science, Technology, Engineering and Mathematics research project.

The project compared aluminum and composite bats. Many softball teams now use bats made of composite fibers instead of aluminum bats, believing composite bats are better.

Gray, a packaging major, wanted to know more. She is enrolled in the UW-Stout Honors College, and one of the requirements of the program is to complete a research project.

"One of the goals is to pick something you are interested in," said Gray, a senior from St. Cloud, Minn., who was the Blue Devils’ most valuable player in 2012.

Gray worked with physics Associate Professor Jo Hopp to develop the project and enlisted the help of assistant professors Todd Zimmerman and Matt Kuchta.

Gray said the research goal was to measure “the kinetic energy and the velocity of both the ball and bat upon changes of impact."

Translated into yeoman's language: Which bat gives the hitter the best chance to hit the ball harder and get on base?

Softball and science
Gray and her team of physics instructors put together a plan. Armed with a ball, both types of bats, hitting tee and high-speed camera from the physics department Image Lab that records 2,000 frames per second, they headed to the multipurpose room of the UW-Stout Sports and Fitness Center.

Because the team did not have a robotic arm to swing the bat, Gray, a .335 career hitter with 17 home runs, hit the ball off the tee into a net and the action was recorded by the camera. While Gray could not produce the exact consistency a robotic arm could, the team strived to be as consistent as possible.

"The tee was always in the same spot and my feet were always in the same spot," Gray said.

Gray hit the ball 22 times, 11 times with each bat. Then, after an analysis, five swings from the aluminum bat and five from the composite bat were further scrutinized.

"We took the two most common initial bat velocities," Gray said. "From the tests, we were able to determine that the composite bat produced a higher velocity (about 3 percent) of the ball after contact."

While Gray did say the results matched what she had determined over her years in the batter's box, the team needed to rule the results of the test inconclusive at this point.

"There was definitely some human error involved," Gray said. "Even though the composite bat was lighter, I was swinging it slower than the aluminum bat."

The results were also considered inconclusive simply because not enough test swings were taken, but Gray and Hopp considered the project a success.

"I think Alison accomplished a lot on this project," Hopp said. "Plus, she came away with an opportunity to describe what she did with others and share her excitement with them."

Gray said she enjoyed working with professors outside of class and seeing the research and amount of detail required to complete the project.

Will Gray use her research data on the field? "I will probably think about it," Gray said. "But as a catcher, I could tell by the sound of the bat if it was a good hit. As a batter, I can feel it in my hands. When you hit a home run, you don't even feel the bat."

The Blue Devils open their season Wednesday, March 6, with a doubleheader against Luther College in Rochester, Minn.