Determination of a Load Approaches for Aircraft Impacts - The Risks of Nuclear Energy Technology - page 258

Mv Mv
vv MM

+
== +

i -- 11 i i i

i i - 1

2( )

i - 1 i

Fig. 14.3 Discrete spring-mass model for the calculation of the impact load-time function

Fig. 14.4 Non-linear characteristic of normal force spring to describe the deformation

extension of the fuselage axis and the wing and jet engine masses. With this method
the loads can be determined in the time dependent order of reaching the different
impact locations. The sum of all that impact springs provides the integral impact
load-time function in the examined case.
With the help of the mathematical model the different approach situations can be
analyzed. The chronological order of the failure of individual components such as
fuselage, wings and jet engines can be determined. The obstacle can be modelled as
a planar, curved or offset structure. The accuracy of the results is decisively
dependent on how realistic the parameters of the individual aircraft models are.
In addition to the geometry and mass distribution the rigidity and bursting loads
must be available for the different sections of the fuselage.