Elastic properties of a cellular structure with in-plane corrugated cosine beams

Cellular structure cores are potential candidates for support structures of flexible skin. The skin requires low in-plane and high out-of-plane stiffness of the support structure. To overcome these problems, a cellular structure with in-plane corrugated cosine beams having close-to-zero Poisson's ratio to significantly reduce unnecessary stress and strain for one-dimensional morphing application was developed. The elastic properties were theoretically analyzed by energy methods, and verified by finite element analysis. Results show that better in-plane morphing and out-of-plane load-bearing capabilities can be obtained with larger height-to-length ratio, spacing-to-length ratio and vertical beam to cosine beam thickness ratio as well as smaller thickness-to-length ratio. Comparisons on properties with conventional accordion honeycomb were carried out. The results reveal that the cellular structure is of lower in-plane elastic modulus, which shows better in-plane property but weaker out-of-plane load-bearing capability. However, the out-of-plane load-bearing capability can be reinforced by increasing the height-to-length ratio and vertical beam to cosine beam thickness ratio.