Report. Evaluation of The Bat Glove System for Durability Improvements

Transcription

1 Report Evaluation of The Bat Glove System for Durability Improvements Prepared by Patrick J. Drane James A. Sherwood, PhD Baseball Research Center Department of Mechanical Engineering University of Massachusetts, Lowell 15-December

2 Introduction A baseball bat durability study was performed at the UMass Lowell Baseball Research Center for The Bat Glove, Inc. The Bat Glove, Inc. developed a baseball bat reinforcement system that consists of a thin polymeric film applied around the taper region of the bat and promotes its system as a potential remedy to the reduce the number of bat pieces that separate and fly from the batter s box. The purpose of this study was to examine a selection of nearly identical bats, half as produced (no bat reinforcement) and half with the polymeric-film reinforcement applied. The bats were tested in matched pairs, one with and one without the film using the same procedure. High-speed video was utilized to make visual comparisons regarding the break severity between maple bats with and without the application of the polymeric film. Procedure Testing was performed using the Baseball Bat Durability System at the Baseball Research Center. The shipment of 22 bats was analyzed for weight and slope of grain. The 22 bats were submitted by The Bat Glove and manufactured by Old Hickory Bat Company. The profile selected was an RB5, which is a large barrel bat (~2.58-in). The bats were put in matched pairs at the UMLBRC based on the combination of weight and slope of grain so that each pair would have very similar properties. Each pair was given a letter designation. One bat of each pair was randomly selected to be applied with the polymeric film, which was applied by the personnel of The Bat Glove, Inc. who were present during the testing. The primary test plan was to impact the bats at the 14-in. location measured from the barrel end of the bat at a reasonable impact speed that would cause failure. The initial impact velocity was 130 mph, and velocity was ramped up 5 mph for each subsequent impact. The bats were impacted until the bat broke or cracks developed. Six pairs of bats were selected to be impacted on the face side of the bat, which is the side that players have been instructed to hit for bats made of Maple. Four pairs of bats were selected to be impacted on the edge side. The 14-in. location was selected because research and experience has shown that impacts around the 14-in. location have a tendency to result in multi-piece failure. The remaining pair of bats was tested at the 2-in. location to study the effect of the wrap at a less extreme impact location. Results Prior to durability testing, the slope of grain and the weight of each bat were measured. The pre- and post-durability test results are presented in Tables 1 and 2. Table 1 contains all 12 bats impacted on the face grain and Table 2 contains all eight bats impacted on the edge grain. The column denoting the number of large pieces has a 1 for a single-piece failure with no complete separation of a large piece (greater than 1.0 oz.) and denoting 2 for a multi-piece failure with a large piece separation that could fly from the batter s box. 1

3 Table 1. Durability Summary at the 14-in. Location, Impact on the Face Group A B C D F J Configuration Number of large pieces Number of impacts Weight [oz.] Slope of Grain Tangential [degrees] Radial [degrees] Break Velocity [mph] Bat Glove Natural Bat Glove Natural Bat Glove Natural Bat Glove Natural Bat Glove Natural Bat Glove Natural Table 2. Durability Summary at the 14-in. Location, Impact on the Edge Group E H I K Number Number Slope of Grain Final Weight Configuration of large of [oz.] Tangential Radial Velocity pieces Impacts [degrees] [degrees] [mph] Bat Glove Natural Bat Glove Natural Bat Glove Natural Bat Glove Natural An additional pair of tests was completed. The bats in group G were impacted at a location 2 in. from the end of the barrel at an initial velocity of 170 mph. Both of these bats broke after two impacts, and neither broke into multiple pieces. Overall, each of the eleven bats that was wrapped with the polymeric film remained intact during failure, while seven of the 10 natural bats tested at the 14-in. location resulted in multi-piece failures. The Bat Glove System s 100% containment of the failures during this study for impacts at a location that shows a high potential for multipiece failure demonstrates that its use could significantly reduce the number of multipiece bat failures when applied to maple bats. 2

4 High speed video was used to record all of the impacts. Images were captured for the impact resulting in a break. Tables 3 through 13 present images of the breaks. Bats on the left are retrofitted with The Bat Glove System and the bats on the right are natural solid maple bats. Table 3. High Speed Video Images of Breaks Group A 3

5 Table 4. High Speed Video Images of Breaks Group B Table 5. High Speed Video Images of Breaks Group C 4

6 Table 6. High Speed Video Images of Breaks Group D Table 7. High Speed Video Images of Breaks Group E 5

7 Table 8. High Speed Video Images of Breaks Group F Table 9. High Speed Video Images of Breaks Group G 6

8 Table 10. High Speed Video Images of Breaks Group H Table 11. High Speed Video Images of Breaks Group I 7

9 Table 12. High Speed Video Images of Breaks Group J Table 13. High Speed Video Images of Breaks Group K 8

10 Conclusions The Bat Glove System was studied at the Baseball Research Center. The study investigated the durability of marched pairs of bats with and without the polymeric film applied. Ten bats of each configuration were tested at the location 14 in. from the barrel end to determine the containment of failures at this impact location. All 10 of the bats with the Bat Glove System had all of the pieces contained as the bat broke, while seven of the 10 natural bats without the film applied resulted in multi-piece failures. 9