Finite shear-band buckling of a fiber-reinforced slab

An equilibrium solution was obtained for the finite shear-band buckling of a fiberreinforced slab under axial compression, using the idealized theory of continua with the kinematical constraints of incompressibility and inextensibility. It was found that the critical buckling load was GH, the infinitesimal shear modulus G times the thickness H of the slab. The solution, involving discontinuities in deformation gradients at the shear-band edges, was proven to conform of the dissipation inequality (under a certain restriction on the material response), which implies the energetical admissibility of the solution obtained. Furthermore, compression tests of beechwood blocks proved that their buckling patterns of shear band type were similar to the theoretical ones. The experimental and theoretical load-shear curves showed good agreement.