Page 216 - Plastics Engineering

Mechanical Behaviour of Composites 199

and
1 1
Ex = =- = 24.26 GN/m2, E, = =- = 12.7 GN/m2
s11 522
1 2
Gxy = -- = 6.9 GN/m , vxy = -Ex??21 = 0.627
s66
vYx = -EyS12 = 0.328
Also,

Ex = 2.06 x ly = -1.29 = -3.12 10-~
Note that

As cry = 0 in this Example

vxy = -- = 0.627 as above
E'
EX
(ii) Alternatively using the Plate Constitutive Equation Approach.

N, = oxh = 100 N/m, N, = 0, Nxy = 0.

8.37 x 104 1.65 x 104 4.84 x lo4 1
2.06 x 16 4.86 x lo4 8.37 x 104
A= 4.86 x 104 3.76 x 104 1.65 x 104 N/mm
1
6.86 x lo4 1.62 x 104 2.79 x lo4
D= 1.62 x lo4 1.25 x 104 5.51 x 16 N mm
2.79 x io4 5.51 x io3 1.61 x io4
a = A-' and d = D-' (since B = 0)
2.06 10-~ -1.29 x 10-~ -3.12 x 10-~
8.89 x
-1.29 x 3.93 x 7.16 x 1 mm/N
-3.12 x 8.89 x