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
10 /
hoop
pr
t
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,
6
6
12
1
2
0.28,
0.02
10
/
,
22.5 10
/
o
o
C
C
,
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
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 PETERIFJU
 10%, 50%, 2m, 4 mm, 0.125 mm, graphite‐epoxy

Click to edit the document details