THE CHARACTERISTICS OF BASEBALL BATS MANUFACTURED BY DIFFERENT MATERIALS

Abstract

Bamboo is a new material to manufacture baseball bat which has the low cost and fast life cycle advantages. But there is no research has been done to study the performance of bamboo bat. This research used three non-destructive testing (NDT) methods including ultrasonic testing method, stress wave testing method and tap tone frequency analysis system (TTFAS) to determine the performance difference among different bat materials. The testing specimen were five baseball bats using four different materials (bamboo, bamboo & wood, wood, and aluminum). The results showed that there are significant correlations among three NDT methods in bats transmit velocities. Therefore, TTFAS method was selected to analyze the characteristics of different material baseball bats because of its low cost and simplicity for the experiment. The results showed the longitudinal and transverse first natural frequencies for each material and the longitudinal and transverse dynamic modulus of elasticity (MOEd). Based on dynamic modulus of elasticity, the stiffness of aluminum bats was higher than the others. KEY WORDS: baseball bat, dynamic modulus of elasticity, stiffness, bat material INTRODUCTION: Modulus of elasticity (MOE) is one of the most important mechanica