Synergistic Effects of Chiral Morphology and Reconfiguration in Cattail Leaves  

作　　者：Zilong Zhao Weixi Huang Bingwei Li Kexing Chen Kuifu Chen Hongping Zhao Xiqiao Feng 

机构地区：[1]AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China [2]Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China [3]College of Sciences, China Agricultural University, Beo'ing 100083, China

出　　处：《Journal of Bionic Engineering》2015年第4期634-642,共9页仿生工程学报（英文版）

摘　　要：Cattail, a type of herbaceous emergent aquatic macrophyte, has upright-standing leaves with a large slenderness ratio and a ehiral morphology. With the aim of understanding the effect of chiral morphology on their mechanical behavior, we investi- gated, both experimentally and theoretically, the twisting chiral morphologies and wind-adaptive reconfigurations of cattail leaves. Their multiscale structures were observed by using optical microscope and scanning electron microscopy. Their me- chanical properties were measured by uniaxial tension and three-point bending tests. By modeling a chiral leaf as a pre-twisted cantilever-free beam, fluid dynamics simulations were performed to elucidate the synergistic effects of the leaf＇s chiral mor- phology and reconfiguration in wind. It was observed that the leaves have evolved multiscale structures and superior mechanical properties, both of which feature functionally gradient variations in the height direction, to improve their ability to resist lodging failure by reducing the maximal stress. The synergistic effect ofchiral morphology and reconfiguration can greatly improve the survivability of cattail plants in wind.Cattail, a type of herbaceous emergent aquatic macrophyte, has upright-standing leaves with a large slenderness ratio and a ehiral morphology. With the aim of understanding the effect of chiral morphology on their mechanical behavior, we investi- gated, both experimentally and theoretically, the twisting chiral morphologies and wind-adaptive reconfigurations of cattail leaves. Their multiscale structures were observed by using optical microscope and scanning electron microscopy. Their me- chanical properties were measured by uniaxial tension and three-point bending tests. By modeling a chiral leaf as a pre-twisted cantilever-free beam, fluid dynamics simulations were performed to elucidate the synergistic effects of the leaf＇s chiral mor- phology and reconfiguration in wind. It was observed that the leaves have evolved multiscale structures and superior mechanical properties, both of which feature functionally gradient variations in the height direction, to improve their ability to resist lodging failure by reducing the maximal stress. The synergistic effect ofchiral morphology and reconfiguration can greatly improve the survivability of cattail plants in wind.

关 键 词：CATTAIL chiral morphology RECONFIGURATION fluid-structure interaction lodging resistance 

分 类 号：TU375.1[建筑科学—结构工程] TN012[电子电信—物理电子学]