SPIRIT AEROSYSTEMS FINAL REVIEW
Jerid Sutton
Daniel Smith
CONCEPT GOAL
To prove an already employed analysis
tool, improve it, or create new analysis
tools for joints and fasteners. In doing
this we would predict load distribution
through the fasteners in the joint.
 Being able to predict load transfer at a
fastener could be very useful to a stress
analyst.

DESIGN TEST CONCEPTS

Load Distribution

Fastener arrangement
and spacing has a major
effect on the distribution
of a load
LOAD TRANSFER THEORY
If the fastener is bigger in diameter it
attracts more of the load
 In a flexible joint the first fastener transfers
the most load
 Fastener configuration effects load
distribution

SPIRIT DESIGN CONSIDERATIONS
Aluminum (2024-T3)
 ½” to 2” total joint thickness
 Fasteners

Bolts and Nuts (Hi-Loks)
2. Rivets
3. 3/16” to 3/8” diameters
4. Materials – titanium, A-286 Steel, Nickel
Alloy
1.
TEAM DESIGN CONSIDERATIONS
Availability of testing equipment
 Using Aluminum 2024-T1 1/8” and 3/16” Plate
 Blind Rivets

 3/16”
Diameter
 Aluminum
 Stainless Steel
 Titanium
TEAM DESIGN CONSIDERATIONS

Nut and Bolt Combination
 ¼”-3/16”
Diameter
 Stainless Steel
 Grade
8
 Grade 6
PSU TESTING CAPABILITIES

Standard Tension Tests
 11,000

lb Maximum Tensile Force
Software
 Pro-Mechanica
 ALGOR
FEA
FEA
STANDARD TEST PROCEDURE
Search ASTM standards for tension testing
procedures
 Predict stress in predetermined specimen
using stress and strain
 Verify testing device by comparing results to
predicted ultimate strength of the specimen

CALCULATION COMPARISON
1040 Cold-drawn Steel
 Stress = Force/Area
 Sample Calculation

 6,250
lb/(.25in X .5in) = 50,000 psi
 Compare with Pro-Mechanica Analysis Results
TENSILE TEST RESULTS IN PRO MECHANICA
MANUFACTURING PLAN
Manufacturing Plan
Group Name:
Date:
Spirit Fatigue Testing
1/31/2007
Oper. #
Description
Machine
Material
Time
# Parts
1
Plate Specimen
Cut-outs
Water Jet
.375 Plate
2024-T3
1hr
40
2
Drill Fastener Holes
Drill Press
.375 Plate
2024-T3
2hrs
40
3
Clean Burred Edges
Within Tolerance
1hr
40
4-A
Bolting Test
Specimen Together
Ratchet
Test Pieces
.5hr
20
4-B
Riveting Test
Specimen Together
Riveting Die
Test Pieces
1hr
20
Belt Sander Test Specimen
2024-T3
RIVETED JOINT CONCEPT
Two partial dog-bone specimen held together
by inline rivets
 Requires Spirit to assemble the specimen
 Surface finish has to be capable of adhering a
strain gage

FIRST JOINT DESIGN
FINAL SPECIMEN DRAWING
TOLERANCE AND QUALITY ISSUES
Measured every specimen cut out and
scrapped anything that was not within .1” of
tolerance
 Some holes that were drilled didn’t properly
line up so those parts were scrapped as well
 When parts were cut out and drilled we had to
debur edges so there were no sharp corners for
safety reasons

RIVET INSTALLATION
CLOSE UP OF INSTALLATION TOOL
RIVET INSTALLATION BLOCK
RIVET SHEAR STRENGTH CALCULATION
Yield Strength or 2024 = 47000psi
 YS = F/6x[ d2/4]
 47000 = F/6x (.250)2/4
 F = 14,628lbs to shear rivets
 The Zwick tensile test machine can only go to
10,000lbs safely so it is not possible to break
the specimen here.

STRAIN GAGE FUNDAMENTALS

Fundamentally, all strain gages are designed
to convert mechanical motion into an electronic
signal. A change in capacitance, inductance, or
resistance is proportional to the strain
experienced by the sensor. If a wire is held
under tension, it gets slightly longer and its
cross-sectional area is reduced. This changes
its resistance (R) in proportion to the strain
sensitivity (S) of the wire's resistance.
STRAIN READING
PREPARING FOR TESTING
STRAIN GAGES
RECORDING STRAIN
TEST PIECE IN MACHINE
CLOSE-UP OF TEST PIECE IN MACHINE
FINITE ELEMENT ANALYSIS IN PRO-E
ELONGATION PREDICTION
TEST RESULTS FROM ONE SPECIMEN
Force (lbs)
Force (N)
1000
4448
2000
8896
3000
13344
4000
17792
5000
22240
411
426
418
262
348
21
7
118
40
21
487
356
267
121
118
290
150
246
84
81
505
219
217
6
41
425
245
206
129
76
530
186
196
50
10
551
158
229
145
90
651
151
140
125
45
677
330
247
150
94
Strain Concentrations (sum)
1
2
3
4
5
6
7
8
9
10
411
426
418
262
348
21
7
118
40
21
898
782
685
383
466
311
157
364
124
102
1403
1001
902
389
507
736
402
570
253
178
1933
1187
1098
439
517
1287
560
799
398
268
2584
1338
1238
564
562
1964
890
1046
548
362
Gage readings are to 10-5
Elongation (mm)
1.6
2.7
3.6
4.5
5.4
Strain
1
2
3
4
5
6
7
8
9
10
INTERPRETATION OF RESULTS
At this point we have a few excel programs from
Spirit but need their assistance in manipulating
them to work with our results.
 The excel program supplied by Spirit is made to
correspond with many different numbers of
fasteners and we do not know yet how to get it
to calculate the load at only 3.

Material
Provided By
Cost to us
.072 Plate
PSU
Free
Rivets
Spirit
Free
Strain Gages
PSU
Free
Equipment
PSU & Spirit
Free
Week 1
Week 2
Week 3
Week 4
Tasks
October
Concept
Literature Review
Pricing
November
Budget
Funding Proposal
Final Proposal
December
Concept Review
Break
Break
Week 1
Week 2
Week 3
Tasks
January
Concept Review
Design And Review
February
Design And Review
Manufacturing Plan
March
April
Manufacturing
Break
Spirit Conciliation 1
Break
Strain Gage Application And
Testing
Testing Results Review
May
Spirit Conciliation 2
Week 4
QUESTIONS?