Civil Engineering Reference
In-Depth Information
Fig. 14.16
Massive structure of the nose tire including steering mechanism
Fig. 14.17
Inner and outer landing gear groups with cylinder and struts
The outer landing gears which are located slightly in front are outwardly
suspended from the wing. They retract inward such that the wheels, axle and
longitudinal axle lay in the fuselage directly in front of the inner landing gears.
The approx. 4.5 m hydraulic cylinder comes to rest perpendicular to the longitudi-
nal axis of the plane in the rear section of the wings. About half of the mass can be
assigned to the fuselage and the inner wing section each (Fig.
14.17
).
Figure
14.18
shows a simplified plot of a possible total mass distribution along
the aircraft axis. There is an abrupt rise in the mass distribution curve at around
22 m from the nose of the aircraft due to the beginning of the wings and tanks.
To determine the impact load-time function the distribution of the bursting loads
for the individual aircraft sections is needed in addition to the mass distribution. As
mentioned above this determination is relatively difficult and brings with it a degree
of uncertainty. The integral bursting load distribution over the longitudinal axis
must be derived from the respective structural dimensions and rough estimates
concerning the rigidity of individual cross sections. As a reminder it should be
noted that the bursting load distribution only has a secondary influence on the
results of the calculations at higher speeds which are of interest, such that the
uncertainty of the assumptions seems acceptable.
