1. Brandon White 1/31/2008 Structures Group Contact Interface Loads Inertia Matrices / Structures Code
AAE 450 Spring 2008

2. Inertia Matrix Math Model
Currently calculates Ixx, Iyy, Izz at the tip of the nose cone.
Assumes ALL products of inertia (ex. Ixy) equal to zero (vehicle is symmetric in radial directions)
Outputs values at different time steps.
First Stage: Full Propellant, Empty Propellant
Second Stage: Full Propellant, Empty Propellant
Third Stage: Full Propellant, Empty Propellant
Help provided by CJ Hiu (Thanks!)
AAE 450 Spring 2008
Structures

3. Tank Specification Model
Sizes the stages of the rocket based on inputs from propulsion data.
For each stage, Inputs: Tank Material, Tank Shape, Prop Type, Prop Volume, Mass, Chamber Pressure, Launch Vehicle Diameter.
Outputs: Tank Dimensions and Masses, Stage Dimensions and Masses, Inert Mass Fractions for each stage.
Future Work
Transfer Inertia Matrix to the Center of Mass
Incorporate Internal Structure (Bulkheads, Mounts, Stringers, etc) to Tank Specification Model
AAE 450 Spring 2008
Structures

4. Backup Slides – References
Bedford, A., Fowler, W., and Liechti, K.M., Statics and Mechanics of Materials, Prentice Hall, Upper Saddle River, NJ. 2003
Strauss, Chris. “Scaling_Program.xls”
Thanks to Propulsion members J. Beasley, N. Wilcox, S. Bluestone, D. Lattibeaudiere for example inputs!
AAE 450 Spring 2008
Structures

5. Backup Slides – Example Output
Stage
Prop Type
Prop Density (kg/m^3)
Prop Volume (m^3)
Chamber Pressure (MPa)
Tank Shape
Tank Material 1
Solid 5 10
Cylinder X 2 3
0.5
Used Chris Strauss’ Scaling measurements for stage Diameter at 5kg Payload (Scale 2)
Tank Material was varied
AAE 450 Spring 2008
“Structures Group = A OK!” – Time Magazine

6. Backup Slides “Structures: Built on Strong Foundations” – USA Today
AAE 450 Spring 2008
“Structures: Built on Strong Foundations” – USA Today

7. Backup Slides
AAE 450 Spring 2008
“The way to get started is to quit talking and begin doing” – Walt Disney

8. Backup Slides – Inertia Matrices for Example
First Stage, Full
First Stage, Empty
Second Stage, Full
Second Stage, Empty
Third Stage, Full
Third Stage, Empty
- Aluminum 7075 Case
AAE 450 Spring 2008
“You can take my word for it.” – Levar Burton