title: Self-adaptive formation of uneven node spacings in wild bamboo.
abstract: Bamboo has a distinctive structure wherein a long cavity inside a cylindrical woody section is divided into many chambers by stiff diaphragms. The diaphragms are inserted at nodes and thought to serve as ring stiffeners for bamboo culms against the external load; if this is the case, the separation between adjacent nodes should be configured optimally in order to enhance the mechanical stability of the culms. Here, we reveal the hitherto unknown blueprint of the optimal node spacings used in the growth of wild bamboo. Measurement data analysis together with theoretical formulations suggest that wild bamboos effectively control their node spacings as well as other geometric parameters in accord with the lightweight and high-strength design concept.
authors.affiliation: Department of Environmental Sciences, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi 400-8510, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shima
authors.affiliation: Division of Engineering and Policy for Sustainable Environment, Faculty of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Sato
authors.affiliation: Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Higashi-ku, Kumamoto, Kumamoto 862-8502, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Inoue
mesh_terms: D001696:Biomechanical Phenomena; D055595:Mechanical Phenomena; D008954:Models, Biological; D006109:Poaceae / Q000254:growth & development*