Dynamic Analysis of Aircraft Floors

Resumo

In this paper, we present a study of the dynamic analysis of aircraft floors. These are usually constructed
of either composite materials plates or metal plates resting on longitudinal spars. In either case, bending of multiple
materials layers must be considered. As we are studying vibrations, that is, small displacements about a static
equilibrium configuration, small strains are also to be expected, leading to validity of the assumption of linear
behavior of all involved materials. Further, we also consider valid Bernoulli-Euler’s Hypothesis that plane sections
remain plane after bending, that is, strains are linearly proportional to the distance of a particular layer to the
neutral axis of the section, whose position must be determined via equilibrium considerations. Thus, an equivalent
Young’s Modulus can be determined. After this phase of the analysis, usual linear vibration frequencies and modes
computation can be carried out either via the Finite Element Method or closed form solutions available in literature.
We also present forced vibrations due to people motion on the floor using a Fourier approach.