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EAS4240/6939 Project – Phase I
A cylindrical pressure vessel of radius 2m is to be designed for pressure of 1 MPa (about ten
atmospheres). If the pressure vessel were to be designed from aluminum with a yield stress of 500 MPa,
then it would be designed by the hoop stress
6
/2
1
0
/
hoop
p
rt
t
, so that the required thickness
would be 4 mm. You are to design the skin from graphite
‐
epoxy with the following properties (as given
in Example 6.3.2):
X
t
=X
c
=1500 MPa, Y
t
=40 MPa, Y
c
=246 MPa, S=68 MPa, E
1
=181 GPa, E
2
=10.3 GPa,
G
12
=7.17 GPa,
66
12
1
2
0.28,
0.02 10
/
,
22.5 10
/
oo
CC
,
t
ply
=0.125
mm. To calculate the
thermal stresses, use the cure temperature as 170
o
C and operating temperature of 20
o
C.
1.
Use the maximum strain criterion to design the lightest balanced and symmetric laminate that
can carry safely the loads. Define the axial direction as the x direction, and then you expect a
laminate that will have average ply orientation larger than 45
o
, because the average axial stress
is half of the average hoop stress. For this part, allow the number of plies to be a continuous
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This note was uploaded on 06/06/2011 for the course EAS 4240 taught by Professor Peterifju during the Spring '08 term at University of Florida.
 Spring '08
 PETERIFJU

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