Environmental Engineering Reference
In-Depth Information
The. velocities. of. propagation. of. longitudinal. waves. in. different. angles.
with.a.step.of.15°.are.determined.using.Equation.(6.17)..From.these.veloci-
ties,.the.modulus.of.elasticity.is.computed.using.Equation.(7-9).and.Equation.
(11-14)..The.values.of.the.coeficient.introduced.into.Equation.(2).are:
.
Eϕ=.kϕCϕ
2
ρ(1.-.μ
1ϕ
μ
2ϕ
).
(6.18)
where.the.kϕ.are.computed.by:
k
z
.
k
φ
=
.
(6.19)
4
2
4
cos
φ
+
b
cos
2
φ
+
c
sin
φ
o
o
where:
k
k
k
k
-
c
+
1
4
c
z
y
; bo =
z
45
o
=
o
The. difference. between. the. values. computed. by. Equation. (6.17). and.
Equation.(6.18).is.only.about.5.percent,.which.proves.that.the.values.obtained.
by.the.present.nondestructive.method.are.acceptable.(see.Table.6.5).
Intent. coeficients. of. thermal. expansion. were. in. the. radial. direction.
α
1
=. .118. cm/cm/°C. /3.8*10
-3
. in/in/F;. in. tangential. direction. α
2.
=.. 115. cm/
cm°C/3.71*10
-3
. in/in/F;. intent. coeficient. of. thermal. expansions. in. an. arbi-
trary.direction.were.determined.as.α
12.
=.2sinθ*cosθ(α
1
-α
2
).
6.1.3
Conclusions
.
1.. Turbine.wind.blades.applications.utilize.hybrid.reinforced.compos-
ites.for.the.huge.blades.that.replace.traditional.iberglass.blades.
TABLE 6.5
Modulus.of.Normal.Elasticity.Depends.on.Angles
E
ϕ
*10
5
,
kg/cm
2
Eq.(6.17)
E
ϕ
*10
5
,
kg/cm
2
Eq.(6.18)
Angleof
Degree
C
ϕ
m/sec
μ
ϕ
k
ϕ
Error,%
0
0.13
0.855
4350
3.4
3.3
3.0
15
0.20
0.86
4150
3.1
2.9
5.0
30
0.30
0.835
3950
2.6
2.5
4.0
45
0.34
0.80
3800
2.28
2.2
3.5
60
0.13
0.812
3900
2.29
2.38
4.0
75
0.128
0.824
3940
2.48
2.4
3.5
90
0.10
0.840
3900
2.56
2.46
4.0
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