Investigation of mechanical properties of re-entrant structure

Conventional re-entrant structure is a cell structure, which has low stiffness. Improving the stiffness and mechanical properties of the re-entrant structure will ensure its application areas to extend. In this thesis, the mechanical properties of the re-entrant structure were investigated. New re-entrant structures were designed to improve the mechanical properties of the re-entrant structure. In order to determine the accuracy and consistency of the numerical analyses of the designed structures, the results of an experimental and analytical study in the literature were utilized. The effects of boundary conditions and aspect ratio on structural behavior were investigated. Compared with the literature, the aspect ratio that converges more to analytical results was obtained. Developed re-entrant structures in terms of mechanical properties were compared with the conventional re-entrant structure. The Poisson ratios and stiffness of the developed structures increased compared to the conventional structure. The aspect ratio optimizations of the developed structures were carried out and the changes of the mechanical properties with the cell wall angle and cell wall length were investigated. As a result, it was found that the aspect ratio is a significant parameter for the consistency of the analysis results. In addition, it has been shown that the mechanical properties of the re-entrant structure can be adjusted to different applications via small changes in the cell wall geometry.