280
X. Zhang and Q. Zhang
Fig. 22.8 Internal energy
history curves of different
shapes of bird impacting on
flat blade
The damage of the flat blade can also be evaluated by the internal energy absorbed
in birdstrike. Figure 22.8 shows the internal energy history curves of the flat blade.
The flat blade absorbs largest energy under the impact of the spherical bird, reaching
29.72 kJ. The energy absorption of the flat plate caused by ellipsoidal bird is the
smallest.
Table 22.3 shows the birdstrike results of the four shape birds. The spherical bird
is the most destructive in terms of the maximum displacement of the flat plate, the
peak contact force and the energy absorption of the flat blade. The destructive effect
of the cylindrical bird with hemispheres at both ends ranks second. Cylindrical bird
and ellipsoidal bird have different ranks in different evaluation indexes. It can be
seen from Figs. 22.6, 22.7 and 22.8 that the contact force, energy absorption and
deformation of the birdstrike caused by the spherical bird occur earliest. This is
because the spherical bird has the smallest aspect ratio, so the kinetic energy of bird
can act on the flat blade in a shortest time. This is why the spherical bird has the
strongest destructive power.
Table 22.3 Impact response of four birdstrike models
Bird shape
Maximum
displacement
[mm]
Peak contact force
[kN]
Maximum energy
absorption[J]
Cylinder
72.50
327.08
20.27
Ellipsoids
69.88
361.08
19.98
Sphere
81.09
477.44
29.72
Cylindrical with
hemispheres at both ends
73.62
373.73
22.33
X. Zhang and Q. Zhang
Fig. 22.8 Internal energy
history curves of different
shapes of bird impacting on
flat blade
The damage of the flat blade can also be evaluated by the internal energy absorbed
in birdstrike. Figure 22.8 shows the internal energy history curves of the flat blade.
The flat blade absorbs largest energy under the impact of the spherical bird, reaching
29.72 kJ. The energy absorption of the flat plate caused by ellipsoidal bird is the
smallest.
Table 22.3 shows the birdstrike results of the four shape birds. The spherical bird
is the most destructive in terms of the maximum displacement of the flat plate, the
peak contact force and the energy absorption of the flat blade. The destructive effect
of the cylindrical bird with hemispheres at both ends ranks second. Cylindrical bird
and ellipsoidal bird have different ranks in different evaluation indexes. It can be
seen from Figs. 22.6, 22.7 and 22.8 that the contact force, energy absorption and
deformation of the birdstrike caused by the spherical bird occur earliest. This is
because the spherical bird has the smallest aspect ratio, so the kinetic energy of bird
can act on the flat blade in a shortest time. This is why the spherical bird has the
strongest destructive power.
Table 22.3 Impact response of four birdstrike models
Bird shape
Maximum
displacement
[mm]
Peak contact force
[kN]
Maximum energy
absorption[J]
Cylinder
72.50
327.08
20.27
Ellipsoids
69.88
361.08
19.98
Sphere
81.09
477.44
29.72
Cylindrical with
hemispheres at both ends
73.62
373.73
22.33