Numerical and Experimental Studies on the Deformation of Missing-Rib and Mixed Structures under Compression

Abstract

Herein, the deformation and properties of cellular structures of missing-rib (MR) model and mixed structures (MSs) are studied experimentally and numerically. Samples with different beam angles and lattice patterns 3D printed with thermoplastic elastomer (TPE) are tested in uniaxial compression. Parametric finite-element models are developed and used to simulate structures of different sample dimensions and lattice patterns with a particular focus on beam–wall contacts. Structures with different sizes and aspect ratios, beam angles, and lattice patterns are comparatively studied. The numerical results show a good agreement with the experimental data on samples of various sizes/patterns. The main deformation modes and key stages of the corner edge–wall contact and structure deformation are presented, and the key mechanism is analyzed. Poisson's ratio and stability of the auxeticity of different structures are established. The link between the structural and auxeticity stabilities and the characteristic of the corner edge–wall contact in MR and MSs are discussed. The MSs with alternative MR columns at opposite orientations show a better shape stability and higher critical strain for a stable auxeticity.