Environmental Engineering Reference
In-Depth Information
TABLE 5.6
Fatigue.Compression.and.Interlaminar.Strength.Prediction.for.Graphite/Epoxy.
Composites.(Second.Approach)
σ
s*
10
-3
MPa/
psi
σ
m*
10
-3
MPa/
psi
S
j*
10
-3
MPa/
psi
L(t)
Parameter
t
Φ
(t)
(equation
(5.71))
Fatigue
Strength
MPa/psi
σ
-1*
10
-3
.34/50
.34/49.16
.023/3.46
.070
.279
.721
.29/36.05
τ
s*
10
-3
MPa/
ps
τ
s*
10
-3
MPa/
psi
S
τ
*10
-3
MPa/
psi
t
1
MPa/
psi
L(t
1
)
Φ
(t
1
)
τ
-1*
10
-3
.068/10
.068/9.95
.004/.65
.076
.299
.701
.048/7.01
TABLE 5.7
Density.of.Probability.Laplacian.Function.(Second.Approach.Equation.(5.88))
t
0
1
2
3
4
5
6
7
8
9
0,0
0,0.
000
040
080
120
160
199
239
279
319
359
0,1
398
438
478
517
557
596
636
675
714
753
0,2.
793
832
871
910
948
987
.026
.064
.103
.141.
0,3
792
217
255
293
331
368
406
443
480
517
0,4.
.554
591
628
664
700
736
772
808
844
879.
0,5
915
950
985
.019
.054
.088
.123
.157
.190
.224
0,6
257
291
324
357
389
422
454
486
517
549
5.9
DynamicAnalysis:FourierFunctionfor
PredictionofFatigueLifecycleTest
5.9.1
Introduction
In.section.5.8,.we.found.the.optimum.parameters.of.iberglass/carbon.using.
the. Weibull. analysis.. This. section. (5.9). describes. how. Fourier. function. can.
predict.fatigue.life.
Light. weight. and. high. strength. anisotropic. composites,. such. as. carbon/
carbon,. graphite. epoxy,. iberglass,. etc.,. under. different. combinations. of.
applied. stress. components. (biaxial. and. triaxial. stress. conditions). pose. a.
challenge.to.designers.for.establishing.reliable.failure.criterion..Stimulated.
stress.components.in.a.composite.turbine.disk.under.the.inluence.of.centrif-
ugal.loads.and.temperature.are.a.typical.example..In.this.research,.we.pro-
pose.to.use.Hook's.law.relationship.between.strain.and.stress.components.
including.effect.of.thermoelasticity.called.the.Duhamel-Neumann.law..Our.
concept. was. based. on. determining. the. stress. parameters. using. equations.
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