Finite Element Study to Compare the Performance of

Wood and Metal Baseball Bats

James Cain10/17/14

Model a baseball and baseball bats in Abaqus/CAE

Perform a dynamic analysis on the bat-ball interaction in Abaqus/Explicit

Modify models with different physical properties such as material, mass, and size

Compare the analytical results of the bat performance to experimental data

Problem Description

Baseball consists of four different materials◦ Cork◦ Rubber◦ Wool◦ Cowhide

Ball Properties

Material Properties of a Baseball

Density (lb/in3) Short-Time Shear

Modulus (psi)

Long-Time Shear

Modulus (psi)

Decay Constant Bulk Modulus

(psi)

.028 4498 1492 5025 13495

Average baseball diameter is 2.90”

Ball Geometry

FEA model of a baseball

Bat materials chosen are ash, aluminum, and aluminum BBCOR

Research for aluminum BBCOR properties is ongoing

Bat Properties

Material Properties of Ash

Density

(lb/in3)

Elastic Modulus (psi) Shear Modulus (psi) Poisson’s Ratio

E1 E2 E3 G12 G23 G13 ν12 ν23 ν13

0.028 2.02x106 1.93x105 2.13x105 1.78x105 2.03x104 1.20x105 0.4 0.5 0.5

Material Properties of Aluminum

Density (lb/in3) Elastic Modulus (psi) Poisson’s Ratio

0.0975 10x106 0.33

Bat length, barrel diameter, and handle diameter are same size for all three bats◦ Length: 34”◦ Barrel diameter: 2.5”◦ Handle Diameter: 1.0”

Ash bat is solid, whereas aluminum bats have solid handle and hollow barrel with 0.1” thick wall

Bat Geometries

Bat Geometries

FEA model of a wood baseball bat

Bat Geometries

FEA model of the aluminum bats showing hollow barrel

FEMs of baseball and bats created Material properties assigned to models

◦ Baseball = Viscoelastic◦ Wood bat = Orthotropic◦ Aluminum bat = Elastic

Assembly and steps created Interactions and constraints applied to bat and

ball Boundary conditions and predefined fields

defined Bat and ball meshed with tetrahedral elements

FEM Progress

Meshed Baseball

Meshed Baseball Bat

Milestones◦ Research material properties for BBCOR aluminum bat◦ Research experimental data on wood and metal baseball bat

performances◦ Run FEM to determine effects of different variables and process results◦ Compare FEA results to experimental data

Deadlines◦ Second Progress Report October 17, 2014◦ Final Draft November 7, 2014◦ Preliminary Final Report November 28, 2014 ◦ Final Report December 12, 2014

Milestones/Deadlines