The goal of this paper is to investigate the pattern transformation in auxetic material microstructure in compression loading. Nonlinear behavior resulting from large microstructural beams deflection and buckling is analysed. Deformation study in compression test is performed using ABAQUS by conducting finite element calculation. Timoshenko beam elements are used for material microstructure discretization. Calculations lead to obtaining nonlinear equilibrium paths. The analysis allow to asses values of critical stress and critical strains. Specimens of increasing size consisting of elemental segments are analyzed. Influence of geometric microstructural parameters on the type of pattern transformation and response of material as equivalent continuum is studied.
