The dynamic behavior of discrete periodic one-dimensional structures is
approached by considering transverse vibrations of structures made of repeated
unbraced frames. Assuming the frame size is small compared to the modal
wavelength, equivalent macroscopic beam descriptions are obtained by the
homogenization method of periodic discrete media. The macroscopic parameters are
expressed as functions of the mechanical and geometrical properties of the frame
elements.
Depending on the order of magnitude (relative to the scale ratio) of the shear
force, the global bending and the inner bending, four families of beams are shown to
be possible. A generic beam governed by a differential equation of the sixth degree is
shown to encompass all the other types.
Simple criteria are established to identify the relevant model for real structures. A
comparison of these theoretical results with numerical modeling is satisfactory even
in the case of weak scale separation. In fact, an investigation of the higher orders
terms shows that zero order descriptions are valid up to the second order. Lastly,
analogies with micromorphic media are discussed.
Keywords
discrete structure, modal analysis, beam theory,
homogenization, micromorphic media
École Nationale des Travaux Publics
de l’État - Université de Lyon
Département Génie Civil et Bâtiment - URA CNRS 1652
rue Maurice Audin
69518 Vaulx-en-Velin
France
École Nationale des Travaux Publics
de l’État - Université de Lyon
Département Génie Civil et Bâtiment - URA CNRS 1652
rue Maurice Audin
69518 Vaulx-en-Velin
France