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

GJGJB rf 0

3ff2

5

ff3f1

421

t1/3h=J

)b

t.052+

b

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