1. Performance Evaluation of Wood and Aluminum Baseball Bats Using Finite Element Analysis
James Cain
12/4/14

2. Problem Description 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, and compare results

3. Material Properties of a Baseball
Ball Properties
Baseball consists of four different materials
Cork
Rubber
Wool
Cowhide
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

4. Ball Geometry Average baseball diameter is 2.90”
FEA model of a baseball

5. Material Properties of Ash Material Properties of Aluminum
Bat Properties
Bat materials chosen are ash and aluminum
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
Material Properties of Aluminum
Density (lb/in3)
Elastic Modulus (psi)
Poisson’s Ratio
0.0975
10x106
0.33

6. Bat Geometries
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 bat has solid handle and hollow barrel with 0.1” thick wall
Bats are modified with different physical properties

7. FEA model of a baseball bat
Bat Geometries
FEA model of a baseball bat

8. FEM 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

9. Results
Bat-Ball Interaction

10. Results
Bat-Ball Interaction

11. Results

12. Results

13. Results

14. Conclusion
Performance of wood and aluminum bats was investigated for different bat masses, bat swing speeds, and ball impact locations
Aluminum bat outperformed wood bat in all analysis when bats were similar in weight
Attributed to smaller moment of inertia of hollow aluminum bat and trampoline effect