Plane strain bifurcation and its relation to kinkband formation in layered materials

A bifurcation analysis was carried out for a class of layered materials whose constitutive behavior were described by the model of Christoffersen and Jensen, 1996. The problem was solved in uniaxial plane strain compression for compressible materials without volumetric plastic strain. The elastic–plastic response of the constituent materials is described by J2-deformation theory and J2-flow theory. Results indicate that bifurcation stresses vary smoothly with wavelength and are sensitive to the moduli ratio between constituent materials and the volume fractions. The results show that there is a transition in the bifurcation mode from an Euler type elastic bifurcation of a slender column made of a composite material to a surface bifurcation mode in the plastic regime for a wide plate. Furthermore, effects of residual stress were also incorporated and studied.