ABSTRACT
The object of analysis is a plane structure reinforced by a system of two families of ribs (Fig. 1). It will be assumed that the number of the ribs is very large and the width of neighbouring ribs may be smoothly variable. The above allows to get a desirable frequency of natural vibrations of this type of structure. The aim of the contribution is to derive the averaged mathematical models describing dynamic behaviour of the structure in plane stress or strain. The formulation of averaged model equations will be based on the tolerance averaging approach (Wozniak et al. 2008, 2010). The general results will be illustrated on presentation by analysis of natural vibrations and long wave propagation in the structure.
