Instability of a Layer on a Half Space

Unstable deformations of an elastic or elastoplastic layer on an elastic or elastoplastic half space, are studied under compressive forces. Various combinations of material properties are considered, e.g., an elastic layer on an elastoplastic half space, elastoplastic layer on an elastic half space, etc. Both the flow and the total deformation plasticity models are used and the corresponding results compared. The results seem to have relevance to the problem of folding of geological formations and crustal buckling under tectonic stresses.