Why do Baseball Bats Break?

in the last three months of the 2008 season over two thousand bats broke in major league baseball games an average of about one per game you've seen this happen a big heavy shard of wood flying into the stands or toward the dugout it's dangerous to the fans and to the players so the MLB decided enough was enough and commissioned a committee of engineers and scientists to provide recommendations about what should be done about all these shattering sluggers hey I'm great today I'm practical engineering we're talking about material science and sports before the early 1990s almost all bats and the majors were made of ash a strong dense hardwood that grows across a large part of the United States that all changed when Barry Bonds broke the season homerun record in 2001 with a maple bat suddenly half the major league players had followed suit the MLB safety and health advisory committee determined that the rise in the use of maple was the primary reason for the increase in broken bats but why would is an anisotropic material that means it's engineering properties are directionally dependent its strength and toughness aren't the same along every axis this is because of how a tree grows the majority of the cells that make up the wood are vertical and elongated you can picture wood as a collection of straws connected together along their edges and material science we would call this a uniaxial fiber composite just like the oak shown here ash is a ring porous wood meaning it has vertical pores which concentrate along the annual growth rings this creates a natural plane of weakness around each ring dealing with anisotropy is one of the fundamental engineering challenges of working with natural materials like wood but the makers of baseball bats have put a lot of thought into this the manufacturers logo on Ashe baseball bats is always placed on the face grain and players are instructed to swing with the logo up this ensures that the baseball contacts a bat on the edge grain and the bending stresses aren't concentrated in the weak axis of the annual growth rings this is the equivalent of hitting on the edge of a deck of cards rather than on the face for the best performance it's crucial that grain runs as close to parallel with the axis of the bat as possible the angle the grain makes with the long axis is called slope of grain and it has a huge impact on overall strength for a long time the wood for baseball bats was Riven or split to produce planks milling lumber this way ensures that the grain is straight because the would naturally separates along the fibers but as Mills grew it became more economical to use saws you can saw through wood in any direction your heart desires so it became necessary to grade bad planks to make sure the slope of grain was small it's easy to grate ash because the planes of weakness are so visible the annual growth rings create nice clear lines but wood has another natural plane of weakness radially from the center of the tree look at the end of any log that's had a bit of time to dry and you can see this unlike reinforced hash maple is diffuse porous that means it's pores are spread throughout the wood rather than being concentrated along the growth rings at first glance this seems like a good thing since you no longer have planes of weakness along the Rings but what the committee found was exactly the opposite without the porous growth rings the weakest planes in maple are those that are radial from the center of the log but these planes don't have a strong visual cue like growth rings so it's more difficult to grade maple blanks for sloped of grain bat manufacturers were used to keeping the growth ring straight along the bat but many didn't recognize the need to ensure that the grain was straight in the orthogonal direction as well the MLB safety and health advisory committee determined that the majority of bats were failing due to slope of grain and you can look through pictures of broken bats and see this oval-shaped failure plane that's characteristic for a slope of grain failure the Committee issued a list of recommendations that was immediately adopted by the MLB to help reduce the number of broken bats including two key changes to how bats are manufactured first bat makers are required to rotate the logo placed on maple bats by 90 degrees since the weakest planes in maple our radial to the log and not the growth rings maple bats are stronger when the face grain is used as the hitting surface secondly manufacturers must place a dot of ink on the face grain of all maple bats and this makes it easier to see the direction of grain orthogonal to the growth rings if you look close sometimes you can see this dot on the handle of some bats in the major league games did these changes make a difference well there's still been some accidents with shattering maple bats including one of the worst incidents today when Tyler Colvin had his lung punctured and missed the rest of the 2010 season but overall bat breaks have actually been reduced by half these days on average you'll only see about one break every two games which is quite an improvement oh this that's just a decoration gift for my brother's birthday thank you for watching and let me know what you think if you liked the video I'd really appreciate it if you click that like button and subscribe to the channel if you have any questions or you have an idea for a future topic let me know in the comments below again thank you for watching

Channel: Practical Engineering

Views: 995,750

Keywords: baseball bat, baseball bat break, broken baseball bat, maple vs ash, ash vs maple, practical engineering, tyler colvin, wood engineering

Id: MjIk-4rJkqU

Length: 5min 38sec (338 seconds)

Published: Mon Mar 28 2016