“…In spite of a relatively wide literature concerning statics and dynamics of a single WK-beam (see e.g. [2,3,5,7,8,14,15,19,22,31,37] and references therein), we are not aware of analytic studies which consider the elastic coupling of two or more nonlinear beams of this type. On the other hand, mathematical models of sandwich beam-type and plate-type structures raised a wide interest in the literature, due to their relevance in many branches of modern civil, mechanical and aerospace engineering.…”