November 12, 2003 QDR 1
Team 5 Structures and Weights QDR #2Team 5 Structures and Weights QDR #2
• Scott Bird• Mike Downes• Kelby Haase• Grant Hile• Cyrus Sigari• Sarah Umberger• Jen Watson
November 12, 2003 QDR 2
PreviewPreview
• Walk Around
• Sizing Criteria
• Material Selection
• Wing Box Properties
• Pod Support
November 12, 2003 QDR 3
Walk-AroundWalk-Around
Data Boom
Pod
Engine
Tail Dragging Landing Gear
Pod Entrance
November 12, 2003 QDR 4
Wing Box Design Sizing CriteriaWing Box Design Sizing Criteria
• Maximum Bending Stress– Iy>=My*z/σxx
• θ<1 degree at tip
• Deflection at tip <=2in
)3(6
)()(
2
axEI
aLiftxw
c
1/4c Lift
ba
Lift
November 12, 2003 QDR 5
Wing Box PropertiesWing Box Properties
Aluminum Balsa Spruce Pine
Front Web thickness (in)
.12 .125 2.1242.125
.66.75 .708.75
Rear Web thickness (in)
.024.025 .025 .12.125
.12.125
Wing Weight (lbf)Front Spar Only
9.25 9.28 5.75 7.6
Front Spar- Tip Deflection Limiting Criteria
Rear Spar- Tip Rotation Limiting Criteria
November 12, 2003 QDR 6
Final Wing Box PropertiesFinal Wing Box Properties
Material– Spruce (lowest weight)
• Heights defined by airfoil• Front Spar
– I-beam– %20 chord
• Rear Spar– Rectangle– %60 chord
.125in
2.25in
1.2in
.75in
2.88in
November 12, 2003 QDR 7
Performance of Wing BoxPerformance of Wing Box
• Θ=.072 deg
• Tip deflection= 1.77 inches
• Total Wing Weight=– Front Spar – + Rear Spar – + 15 Ribs– =7.4401 lbs
November 12, 2003 QDR 8
Pod SupportPod Support
• My=q*L^2/12– My-maximum bending stress– q=distributed load
• (1/2 pod weight)
– L=length
• Iy>=My*z/σxx
L
q
November 12, 2003 QDR 9
Fuselage LayoutFuselage Layout
November 12, 2003 QDR 10
Results to come….Results to come….
• Wing Failure Analysis
• Wing Attachment
• Boom Sizing
• Fuselage Structure Analysis
• Tail Structure
November 12, 2003 QDR 11
Questions?Questions?
November 12, 2003 QDR 12
Material PropertiesMaterial Properties
Property Aluminum Balsa Spruce Pine
Max bending stress (lb/in^2)
47e3 2.2e3 5656 6.9e3
Shear Modulus (lb/in^2)
4e6 3.13e4 1.73e5 9.38e4
Young’s Modulus (lb/in^2)
10e6 .5e6 1.6e6 1.5e6
Density (lb/in^3)
.0995 .0065 .0145 .0185
”Selection and use of Engineering Materials”, J.A. Charles
November 12, 2003 QDR 13
Appendix (References)Appendix (References)
• ”Mechanics of Materials”, James Gere• ”Selection and use of Engineering Materials”, J.A. Charles
hf
November 12, 2003 QDR 14
Span-wise LoadingSpan-wise Loading
• Assumed Elliptical Loading
• Maximum at Root
• Max bending at root =245 lbf-ft
November 12, 2003 QDR 15
Wing Box Properties (Rotation Requirements)Wing Box Properties (Rotation Requirements)
• Requirement: θ<1 degree at tip
– T=Lift*(distance to shear center)– L=Half span– dis=distance between spars
))(sec)tanh(1( 2221
20
20 LhLLLLB
bTA
20
02
bA
B EIEIA f 20
111
)h
t.052+
h
t.63-(11/3bt=J
5
r
r
r
r3rr
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5
ff3f1
421
t1/3h=J
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t.63-(11/3bt=J
t2+J+2J
ffJ
)h
t.052+
h
t.63-(11/3bt=J
5
r
r
r
r3rr
tr
b
hr
tf
hf
November 12, 2003 QDR 16
Wing Tip Deflection for AluminumWing Tip Deflection for Aluminum
November 12, 2003 QDR 17
Weight of Wing Structure (half span of front spar)Weight of Wing Structure (half span of front spar)
• Weight=density*Cross sectional area*length