An investigation of bat durability by wood species

摘要

Northern white ash had been the wood of choice for Major League Baseball (MLB) bats until the introduction of hard maple in the late 1990s. Since the introduction of maple to the game, there has been a perceived increase in the rate of bats to exhibit multi-piece failures (MPF)-both ash and maple. Lab and field data indicate that while a maple bat is as equally likely to crack as an ash bat, maple is three times more likely than ash to exhibit an MPF. In 2009 MLB implemented a number of additional regulations and inspection processes for the wood billets in an effort to reduce the MPF rate. In 2010, another regulation was added requiring that before any new wood species can be introduced to the game, it must it must obtain approval from MLB Baseball Operations. This paper will describe a proposed wood species certification protocol to quantify its durability relative to ash, where ash is being taken as the acceptable baseline for durability. A demonstration of the protocol is conducted using yellow birch with white ash as the baseline. Finite element models of bats made of these two wood species are used to explore the relationship between wood density and bat durability.