ABSTRACT
Currently, bat performance testing is divided into two excepted standards the ASTM and the NCAA. The ASTM method measures Bat Performance Factors (BPF) of the bat, and the NCAA method uses an air cannon to propel the baseball towards a stationary bat, and then measures the velocity before and after impact to determine the BESR (ball exit speed ratio). Both of these methods are done in a lab setting which is a stable and controlled environment, making them different from field testing. Shenoy et al. (2001) used a constant bat swing speed to compare the response of different bat types. Shaw (2006) used laboratory and field experimental investigations to better understand the relationship of bat properties on batted-ball speeds. Many engineering and physics researchers have developed mathematical models that have enable the calculation of ball exit speeds and bat swinging speeds (Adair, 2002; Nathan, 2000). Based on this, our research used a high speed video camera system to capture the batting parameters (BPF, BESR, Bat COR) during field testing. The non destructive testing (NDT) method was also used to measure the longitudinal and transverse natural frequencies of the bat. Natural frequencies are the key to estimating longitudinal and transverse dynamic modulus of elasticity. This research discusses the correlation between the NDT method results and batting parameters.
