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Team 1: Matthew Gaudioso, Jeff Kandel, Armin Moosazadeh, Stephen Potter, John Emoto-Tisdale Professor Kedward TA: Zi Yie ME 154

Composite Boom Design Status Presentation

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This is a status update presentation for the design of a composite material shuttle boom arm for a group academic project at UCSB. The design need to meet a specific weight, deflection, vibrations and thermal performance requirements. This presentation explains our initial choices and their justifications. It also includes our recommended changes needed for the project to meet the given performance requirements.

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Page 1: Composite Boom Design Status Presentation

Team 1: Matthew Gaudioso, Jeff Kandel, Armin Moosazadeh, Stephen Potter, John Emoto-Tisdale

Professor Kedward TA: Zi Yie ME 154

Page 2: Composite Boom Design Status Presentation

Y

Z

X

Ea, Ia

La

Eb, Ib

Lb

Page 3: Composite Boom Design Status Presentation

Ro=6.5in

D

Ri

h

t

t

b

For our design, we considered these three cross-sections.

The hollow cylinder cross-section was used for Beam A in all configurations.

All three cross-sections were constrained so that the diagonal is 13 inches max.

hi

I-beam

Circle

Square

Page 4: Composite Boom Design Status Presentation

Deflection Stiffness: Case 1 ◦ The result for the deflection was found using a

finite element method and was also found using Castigliano’s Theorem.

Page 5: Composite Boom Design Status Presentation

Deflection Stiffness: Case 1

Castigliano’s Theorem

Energy method for deflection analysis

Very useful when forces act on elastic systems subject to small displacements

bending

Page 6: Composite Boom Design Status Presentation

Deflection Stiffness: Case 2 ◦ Using theory of superposition and using a finite element

method

Page 7: Composite Boom Design Status Presentation

Deflection Stiffness: Case 3 ◦ Using theory of superposition

Page 8: Composite Boom Design Status Presentation

Bending Strength ◦ Bending Moment at which the structure will fail

given the material’s failure stress Fu. ◦ For composite materials the lowest failure stress

was always the compressive failure stress.

Hollow cylinder I-Beam Hollow Square

Page 9: Composite Boom Design Status Presentation

Thermal Deflection ◦ V is the maximum deflection due to thermal expansion.

◦ The section with the higher deflection due to thermal expansion is shown on the tables on the later slides.

T1

T2

Stowed

Released

Page 10: Composite Boom Design Status Presentation

Stowed Frequency

Minimum Flexural

Frequency

32 Hz

Boundary Conditions Pinned ends on beam

Page 11: Composite Boom Design Status Presentation

Weight ◦ Section A for all situations uses the hollow cylinder

geometry to reduce torsion.

𝑊 = 𝜌𝑉 Hollow cylinder

I-Beam

Hollow Square

Page 12: Composite Boom Design Status Presentation

Hollow Cylinder Ro=6.5in Ri=6.44in

I-Beam h=b=9.19in

hi=9.08in t=.056in

Hollow Square D=9.19in T=.07in

Restriction

Deflection 1 (in) 3.4727 3.9228 3.6642 1 in max

Deflection 2 (in) 0.7597 1.2098 0.9511 1 in max

Deflection 3 (in) 4.3743 6.9865 4.5657 1 in max

Failure Bending Moment (in-lb)

2.82*105 2.82*105 2.82*105 550,000 in-lb Minimum due to dynamic launch conditions

Applied Bending Moment due to Temperature gradient (in-lb)

1.96*105 1.36*105 1.92*105 Must be less than failure bending moment above

Weight(lb) 142.7 146.7 146.06 150 lb max

Page 13: Composite Boom Design Status Presentation

No geometry passed all conditions with Aluminum.

Many conditions failed by too large of a margin to consider Aluminum a viable choice.

We considered Titanium next.

Page 14: Composite Boom Design Status Presentation

Hollow Cylinder Ro=6.5in Ri=6.46in

I-Beam h=b=9.19in

hi=9.125in t=.033in

Hollow Square D=9.19in T=.04in

Restriction

Deflection 1 (in) 3.3803 3.8419 3.6119 1 in max

Deflection 2 (in) 0.7395 1.2010 0.9710 1 in max

Deflection 3 (in) 4.1873 6.8301 4.4189 1 in max

Failure Bending Moment (in-lb)

5.84 *105 5.84 *105 5.84*105

550,000 in-lb min due to launch conditions

Applied Bending Moment due to Temperature gradient (in-lb)

7.86 *104 5.3 *104 7.2 * 104 Must be less than failure bending moment above

Weight (lb) 147.3656 149.3139 145.2912 150 lb max

Page 15: Composite Boom Design Status Presentation

Stowed Frequency: Hollow Cylinder

Material Natural Frequency Passes 32 Hz requirement?

Aluminum 9.01 Hz No

Titanium 9.05 Hz No

Aluminum and titanium failed the vibrations test as well. So, we moved on to composites.

Page 16: Composite Boom Design Status Presentation

No basic geometry can allow Titanium to satisfy our requirements.

Part still failed by too large of a margin to consider Titanium a viable design choice.

Isotropic materials are a poor choice.

Composites are now considered.

Page 17: Composite Boom Design Status Presentation

Hollow Cylinder Ro=6.5in Ri=6.43in

I-Beam h=b=9.19in

hi=9.12in t=.036in

Hollow Square D=9in T=.081in

Maximum Spec

Deflection 1 (in) 1.0834 1.4173 1.1756 1 in

Deflection 2 (in) 0.2646 0.7265 0.3722 1 in

Deflection 3 (in) 2.2262 3.9934 2.3570 1 in

Failure Bending Moment (in-lb)

5.943*105

compression

2.295*105

Compression

5.534*105

compression 550,550 in-lb

Bending Moment due to Temperature gradient (in-lb)

5.525*104 6.55*104 5.592*104 550,550 in-lb

Weight (lb) 149.27 149.1 149.47 150 lb

Page 18: Composite Boom Design Status Presentation

Of the cross-sections tested, the hollow circular cross-section proved to be the best for all requirements

Changes in Length ◦ Adding Length to Beam A and removing from beam

B reduces deflection due to torsion by decreasing the lever arm that is deflected.

Changes in Thickness ◦ Adding thickness to beam A decreases all deflection

at the risk of adding more weight.

Page 19: Composite Boom Design Status Presentation

Choosing more 45⁰ Plies to limit deflection ◦ A higher Shear Modulus can decrease the deflection due

to torsion in case 3, but since it corresponds to a lower Young’s modulus the bending deflection in all cases will increase

Choosing Plies to increase Ftu & Fcu

◦ Decreasing the % 45 plies results in higher values of Ftu & Fcu. The higher the values, the better it can withstand maximum applied bending moment

Addition of Torsional springs at elbow may decrease deflection due to torsion for the case 3 out of plane load.

Other composite materials were next considered.

Page 20: Composite Boom Design Status Presentation
Page 21: Composite Boom Design Status Presentation

• For beam A, CFRP, epoxy matrix (isotropic) was used with 40% +/- 45 deg plies and 60% 0 deg plies. For beam B, Boron Carbide was used.

• The strategy for picking the beams was as follows: Beam A: look for an optimization of low density and high

shear modulus Beam B: look for an optimization of low density and high

Young’s modulus • A hollow cylinder was used for both beams. Beam A used the

maximum envelope, whereas beam B used a slightly smaller outer diameter.

• Torsional springs were going to be added to decrease δ3, but the trade-off for decreased δ3 did not outweigh the negative consequence of increased weight.

Materials from CES Software Database

Page 22: Composite Boom Design Status Presentation

Characteristic Value

Length Beam A 300 in

Length Beam B 300 in

Young’s Modulus Beam A 17.08*10^6 psi

Young’s Modulus Beam B 68.5*10^6 psi

Outer Radius Beam A 6.5 in

Inner Radius Beam B 6.357 in

Inner Radius Beam A 6.25 in

Inner Radius Beam B 6.194 in

Shear Modulus Beam A 6.84*10^6 psi

Density Beam A .054 lb/in^3

Density Beam B .085 lb/in^3

Ultimate Tensile Strength Beam A 130.34*10^3 psi

Ultimate Tensile Strength Beam B 81.2*10^3 psi

Ultimate Compressive Strength Beam A 98.6*10^3 psi

Ultimate Compressive Strength Beam B 825*10^3 psi

Coefficient of Thermal Expansion Beam A 2.22e-6

Coefficient of Thermal Expansion Beam B 1.89e-6

Final Design Parameters

Page 23: Composite Boom Design Status Presentation

Stowed Frequency: Hollow Cylinder

Different weight and dimensions (inner/outer radii) in both members of the beam

Cannot treat it as beam with uniformly distributed mass

Solution: Add third pin in middle and treat it as 2 beams

Material Natural Frequency Passes 32 Hz requirement?

CFRP Epoxy Matrix

(40% 45o, 60% 0o)

Boron Carbide

27.74 Hz (Beam A)

42.85 Hz (Beam B)

No

Yes

Beam A Beam B

Page 24: Composite Boom Design Status Presentation

Stowed Frequency: Hollow Cylinder

3 pins (both ends and middle) did not pass minimum requirement of 32 Hz for both beams

Beam A (left beam) failed

Solution: Add fourth pin in midpoint of Beam A and treat it as 3 beams

Beam A1 Beam A2 Beam B

Material Natural Frequency Passes 32 Hz requirement?

CFRP Epoxy Matrix

(40% 45o, 60% 0o)

Boron Carbide

110.95 Hz (Beam A1)

110.95 Hz (Beam A2)

42.85 Hz (Beam B)

Yes

Yes

Yes

Page 25: Composite Boom Design Status Presentation

Design Spec Current Spec Achieved

δ1 1 in 0.85 in

δ2 1 in 0.16 in

δ3 1 in 0.60 in

Frequency

Section 1, Section 2, Section 3

> 32 hz 110.94 hz, 110.94 hz, 42.85 hz

Geometry (length) 50 ft 50 ft

Geometry (Maximum envelope) 13 inches diameter 13 inches diameter

Maximum Weight 150 lb 149.4 lb

Withstand maximum moment 550,000 lb-in 550,570 lb-in

Thermal deflection stowed NA 3.07 in

Thermal deflection released NA -.0102 in

Design Spec vs. Current Spec Achieved

Page 26: Composite Boom Design Status Presentation

Other materials can be tested for more desirable properties that allow the implementation of a safety factor in the design.

More ply orientations can be tested to meet more desirable material properties as well.

Geometrical considerations such as tapering

could be explored to enhance performance. Mechanical behavior such as fatigue strength and

fracture toughness could be studied to ensure a more robust design.