Initial postcritical behavior of sandwich columns with low shear and transverse stiffness

The energetic variational analysis of the initial postcritical behavior of homogenized orthotropic columns presented in a previous paper is here revisited in the specific context of sandwich structures. For this purpose, consideration of the transverse deformation in the core is found to be essential. It is shown that imperfection sensitivity can arise for a certain range of stiffness and geometric parameters. The bifurcation is symmetric and Koiter’s 2/3-power law is followed. Finite element simulations of short columns validate analytical predictions of maximum load reduction due to imperfection sensitivity.