Page 246 - Plastics Engineering

Mechanical Behaviour of Composites 229

Now, for equilibrium of forces F1 = F2 + F3

(rd2/4) + (md)dx

(d/4)dof = -r,dx
Integrating this equation gives

4ry (:t - x)
of = (3.45)
d
This is the general equation for the stress in the fibres but there are 3 cases
to consider, as shown in Fig. 3.30

Stress
I strest

-

Fig;. 3.30 Stress variations in short fibres