LONG WAVELENGTH BIFURCATIONS AND MULTIPLE NEUTRAL AXES OF ELASTIC LAYERED STRUCTURES SUBJECT TO FINITE BENDING

Geometries and rigidities involving the presence of more than one neutral axis during finite (plane-strain) bending of a multilayered elastic (incompressible) block make numerically stiff the differential equations governing the incremental problem necessary to investigate diffuse-mode instabilities. We have developed a compound matrix method to solve these cases, so that we have shown that the presence of two neutral axes occurs within sets of parameters where the elastic system may display long-wavelength bifurcation modes. Following the predictions of the theory, we have designed and realized qualitative experiments in which these modes become visible.