Thesis
A COMPARISON OF FASTPITCH SOFTBALL BAT PERFORMANCE USING ACCELERATED, ILLEGAL, AND NATURAL MEANS
Washington State University
Master of Science (MS), Washington State University
01/2022
DOI:
https://doi.org/10.7273/000004585
Handle:
https://hdl.handle.net/2376/125048
Abstract
Fast pitch softball is a popular and growing sport. High performance softball bats are hollow and often made from one or multiple shells of fiber reinforced composite materials. Composite bats can soften or break-in and increase their performance with use. There are three common break in methods: accelerated break-in for certification (rolling), natural break-in by hitting (hitting), and illegal rolling by bat doctors (bat doctoring). In 2005 illegal bat alteration resulted in a 4% increase in bat performance.
This study has three aims: to analyze the effect of break-in treatment on bat damage; to characterize the life of hit bats and compare them to rolled bats; and to investigate the effect of current bat doctor treatments on the batted ball speed and bat barrel stiffness.
Bats underwent three different treatments – rolling according to the certification standard, automated hitting in a laboratory setting, and bat doctoring by a third party. Ultrasonic inspection was used to non-destructively examine the damage in each composite bat. Bat performance changes were characterized by the batted ball speed and barrel compression measurements.
Ultrasonic images showed different damage signatures for the three treatments. Rolling caused long delaminations down the length of the bat. Hitting caused localized impact damage in the form of ultrasonic attenuation. Bat doctoring did not cause observable damage. The batted ball speed and barrel compression were measured over the life of the bat. Comparing rolled and hit bats showed no statistically significant difference between the performance increases of these two treatments. Bat doctoring did not cause any performance increases.
While rolling and hitting produced different structural damage, their similar performance showed that current bat altering methods are relatively benign.
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Details
- Title
- A COMPARISON OF FASTPITCH SOFTBALL BAT PERFORMANCE USING ACCELERATED, ILLEGAL, AND NATURAL MEANS
- Creators
- Katharine Anne Callahan
- Contributors
- Lloyd V Smith (Advisor)Donald Bender (Committee Member)Karl Englund (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Voiland College of Engineering and Architecture
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 121
- Identifiers
- OCLC#: 1370910703; 99900898740501842
- Language
- English
- Resource Type
- Thesis