Environmental Engineering Reference
In-Depth Information
Y
I
X
O
π
2π
Harmonic Fourier function
FIGURE 5.9
Harmonic.Fourier.function.
.
Y.=.8/π(sin.X.+.1/3
3
sin3X.+.1/5
3
sin5X.+.……..).
(5.92)
Y.=.Σσ
-1x,.
or.Σσ
-1y.
;.X.=.F
ND
;.F
ND
.is.Duhamel-Neumann.function:
.
F
NDX..
=.ΣQ
x
ε
xy.
-.ΣQ
x
α
x
*T.;.F
NDY..
=.Σσ
-1y..
=.ΣQ
y
ε
yx.
-.ΣQ
y
α
y
*T.
(5.93)
Σσ
-1x.
=.8/π(sin.F
NDX
.+.1/3
3
sin3.F
NDX
.+.1/5
3
sin5.F
NDX
.+.……..).
(5.94)
Σσ
-1y.
=.8/π(sin.F
NDY
.+.1/3
3
sin3.F
NDY
.+.1/5
3
sin5.F
NDY
.+.……..)
5.9.3
Experimental Investigation
Prepreg.based.on.reinforced.IM.(intermediate.modulus).iber,.tape.T40/800B.
impregnated. with. tough. epoxy. resin. Cycom
®
. 5320-1. in. tension. direction.
has. strength. equal. to. 2,565. MPa.. Testing. conditions. are:. -100°F(-73°C). (see.
Table 3.5)..We.can.see.anisotropic.character.properties.strength.in.0˚.tension.
in.25.to.30.times.higher.than.in.transverse.direction.90.degree.(see.Table.3.5).
If.sine.of.Duhamel-Neumann.function.F
ND
.equals.strength.σ
-1.
for.one.cycle:
.
sin.F
NDX
.=σ
-1
In.Equation.(5.94),.we.can.sign.as:
Σσ
-1x.
=.8/π(.σ
-1
.+.1/3
2.
σ
-1
.+.1/5
2
σ
-1
.+.……..).
(5.95)
Σσ
-1y.
=.8/π(.σ
-1
.+.1/3
2
σ
-1
.+.1/5
2
σ
-1
.+.……..)
Tension.test.in.0°.direction.IM.Fiber.reinforced.tape.T40/800B.impregnate.
by.Cycom.5320-1.shows.strength.drop.(Figure 5.10).
In. the. horizontal,. we. indicate. number. of. cycles;. in. vertical,. strength.
drop. in. tension. test.. Compression. test. in. 0°. direction,. IM. iber. reinforced.
tape. T40/800B. impregnate. by. Cycom. 5320-1. shows. a. drop. in. strength.
(Figure 5.11).
Shear.strength.test.IM.iber.reinforced.tape.shows.also.a.drop.in.strength.
(Figure 5.12).
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