Optimal Sinusoidal Cellular Structures for Energy Absorption

Abstract

In this investigation, the elastic mechanical properties of the sinusoidal cellular structures were first explored via analytical models. The analytical analysis showed that for linear elastic materials, the amplitude-to-wavelength ratio of the sinusoidal structures is a key geometric parameter to determine the deformation mechanisms. To further evaluate the influences of the geometric nonlinearity, a set of finite element simulations were performed for sinusoidal structures with the same density but various amplitude-to-wavelength ratios. It was found that the optimal amplitude-to-wavelength ratio for the maximum energy absorption corresponds to the transition between symmetric to asymmetric deformation mechanisms. Selected designs were fabricated via a 3D printer (Objet, Connex 260). Mechanical experiments under quasi-static uniaxial compression and cyclic compression were performed on the 3D printed specimens. Finite element (FE) simulations with both linear elastic and nonlinear hyperelastic material models were performed and compared with the experiments. The 3D-printed sinusoidal structures were shown to be re-configurable under cyclic loading.