Buckling of bi-layers under in-plane compression

Abstract

Surface, the front face of any materials or object. Surface properties define the physical appearance, chemical reactivity or stability, optical, friction, mechanical properties etc. To study and manipulate the surface properties is the dire need in present scenario. At present with modern instruments, better understanding of different biological phenomena particularly stability, pattern formation and small scale deformation of membranes have been gained. In the present article a two-dimensional film which is in a frictional contact with the substrate which developed between the film and the substrate using the contact interactions is studied. Surface morphology and stability evolution of a thin elastic film subjected to in-line axial force is investigated. The instability of the 2D thin film under different elastic conditions and boundary conditions is examined using finite element simulation. The response to perturbation in which surface of the film becomes unsteady and forms a wavy pattern without any simultaneous mass transport. A complete picture stability/bifurcation is obtained for different elastic modulus ratios of film and substrate. Result revealed that the wavelength is directly proportional to elastic modulus of the film. The growth rate of perturbations is also analysed. The pattern instability in the thin films which are fixed on a substrate by adhesive forces decreases with the decrease in elastic modulus of the film. Study revealed that the morphology of the film is independent of forces exerted however seems dependence on the nature of the film. The film shows stability in its pattern when its elastic modulus is same as substrate elastic modulus or the ratio of modulus is close to unity. This study will be helpful in in choosing the surface coating to coat over the base material, design material of required properties coating life and estimating the life of coating.