1. Ashley Brawner Neelam Datta Xing Huang Jesse Jones
Structures 2 PDR
Team 2: Balsa to the Wall
Ashley Brawner
Neelam Datta
Xing Huang
Jesse Jones
Matt Negilski
Mike Palumbo
Chris Selby
Tara Trafton

2. Overview Weight determination Fuselage and tail Analysis of wing loads
Wing structure

3. CATIA Model

4. CATIA Model Component locations based on previous CG calculations
Will provide more accurate CG value
Will lead to accurate moments and products of inertia

5. V-n Diagram Design Point: Vertical turn radius = 28 ft
Velocity = 60 ft/s
Load factor = 5

6. V-n Diagram
Maximum Design Load Factor = 7.5

7. Simplifying Assumptions
Modeled lift with elliptic distribution
Approximated airfoil as ellipse for analysis

8. Discretized Wing

9. Bending Load

10. Bending Load t = 0.00025 in t = skin thickness
y = vertical distance from neutral axis
M = bending moment
I = moment of inertia

11. Twisting Analysis T = Torque Cm = Moment Coefficient c = Chord length
q = shear flow
A_bar = Airfoil cross-sectional area
theta = twist angle/unit length

12. Twisting Analysis

13. Wing Skin Material E-glass/Epoxy Known Values weight [oz]
thickness [in] 3
0.0046 4
0.0059 6
0.0093
7.5
0.0107

14. Wing Skin Material Available Materials weight [oz] thickness [in]
cost per square yard
0.5
$6.50
0.58
$6.00
0.73
1.4
0.0021
$4.25 2
0.003
$4.50
2.3
$5.00

15. Fiberglass Weight [lbf]
Wing Skin Material
Wing Area [in^2]
Wing Area [yd^2]
1.130
Fiberglass Weight [lbf]
0.035
Epoxy Weight [lbf]
0.071
Wing Volume [in^3]
Wing Volume [ft^3]
0.277
Foam Weight [lbf]
0.485
Wing Weight [lbf]
0.591
With 0.5 oz E-glass/Epoxy

16. Wing Skin Material

17. Summary Lots of work still to be done…
Wing skin will be 0.5 oz E-glass/Epoxy
Current weight is approximately 0.6 lbf
Questions?

18. Questions?

19. Material Properties Material Properties Table E-Glass Fiber S-Glass
E-Glass
Fiber
S-Glass
E-glass
(Fabric)
Balsa
Wood
Carbon
Polyurethane Foam
Density (lbs/in^3)
0.071
0.072
0.068
0.054
0.065
0.0046
Tensile Strength (ksi)
165
250
62.8
0.16
325
Shear Strength (ksi)
12.9 10
12.2
0.54
10.6
0.2
Longitudinal Young's Modulus (10^6 psi) 6
6.5
3.55
0.0094
21.3
0.0051
Transverse Young's Modulus (10^6 psi)
1.5
1.6
3.45
Shear Modulus (10^6 psi)
0.62
0.66
0.68
0.0085 1
Poisson's Ratio
0.28
0.29
0.11
0.4
0.27
0.25

20. Load Factor – Max Lift
Fix FontSize in Labels

21. Load Factor – Level Turn
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22. Load Factor – Vertical Turn
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23. Wing Centroid

24. Load Analysis

25. CG Approximation

26. CG Approximation BALSA Component weight (lb) x pos (in.) y pos (in.)
Structure
2.26
15.04
0.81
Speed Controller
0.26
6.00
1.34
Batteries
1.25
2.00
Motor
0.59
5.00
Payload
1.00
3.00
-0.50
Gyro
0.01
3.50
1.75
Tail Servos
0.08
7.50
0.54
Receiver
0.04
Total Weight
5.50 CG
8.15
0.77
Aerodynamic Center
9.26