Zhao Zi-Long, Zhao Hong-Ping, Li Bing-Wei, Nie Ben-Dian, Feng Xi-Qiao, Gao Huajian
1] AML &CAMM, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China [2] Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
AML &CAMM, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
Sci Rep. 2015 Jul 29;5:12610. doi: 10.1038/srep12610.
Through natural selection, many plant organs have evolved optimal morphologies at different length scales. However, the biomechanical strategies for different plant species to optimize their organ structures remain unclear. Here, we investigate several species of aquatic macrophytes living in the same natural environment but adopting distinctly different twisting chiral morphologies. To reveal the principle of chiral growth in these plants, we performed systematic observations and measurements of morphologies, multiscale structures, and mechanical properties of their slender emergent stalks or leaves. Theoretical modeling of pre-twisted beams in bending and buckling indicates that the different growth tactics of the plants can be strongly correlated with their biomechanical functions. It is shown that the twisting chirality of aquatic macrophytes can significantly improve their survivability against failure under both internal and external loads. The theoretical predictions for different chiral configurations are in excellent agreement with experimental measurements.
通过自然选择，许多植物器官在不同的长度尺度上进化出了最优形态。然而，不同植物物种优化其器官结构的生物力学策略仍不清楚。在这里，我们研究了几种生活在同一自然环境中但采用截然不同的扭曲手性形态的水生大型植物。为了揭示这些植物中手性生长的原理，我们对它们细长的挺水茎或叶的形态、多尺度结构和力学性能进行了系统的观察和测量。对预扭曲梁在弯曲和屈曲状态下的理论建模表明，植物的不同生长策略与其生物力学功能密切相关。结果表明，水生大型植物的扭曲手性可以显著提高它们在内部和外部负荷下抗破坏的生存能力。不同手性构型的理论预测与实验测量结果高度吻合。
