Figure 11. (a)Tan (δ) vs. Log (N)
graph for the 6AL10b and 6CFRP10b specimens, (b) Stiffness reduction vs
normalized cycle graph for 6AL10b and 6CFRP10b
specimens
Figure 12 shows the effect of impact energy on the damping ratio for the
9AL10b specimen. Increasing impact energy increased the damping ratio
while increasing cycles to failure decreased the damping ratio. After
100 cycles, when the stable region starts, the reduction in the damping
ratio of damaged specimens (5 Joules and 10 Joules) was less compared to
the undamaged specimen.
Damping ratio of undamaged specimens was lower than that of damaged
specimens (Figure 10). The reason for this may be that undamaged
structure transmits vibration more 32.