风荷载下植物叶片自适应特性研究

Research on self-adaptive characteristics of plant leaves under wind load

为了探讨植物叶片抵御风荷载的内因,文章建立2种植物叶片的有叶脉及无叶脉网络模型,并对4种模型承受不同方向风荷载进行数值模拟,分析表明,与无叶脉网络模型相比,有叶脉网络模型在其叶脉体积小于整体叶片体积10%的情况下,却使应力与应变减少95%左右,具有良好的抵抗风荷载的能力;以最小柔度为目标、体积为约束,获得了风荷载激励下植物叶片拓扑图,并与实际叶片网络图对比发现两者具有一定的相似性,说明植物叶片叶脉的分布除了实现自身生理功能之外,反映了生物在外界荷载下的自适应过程。

In order to explore the internal cause of plant leaf＇s resisting wind load,the models with vein and without vein of two different plant leaves were established,and the numerical simulation of the four models under wind load from different direction was carried out.The numerical analytical results show that in comparison to the model without vein,the vein volume of the model with vein is less than 10% of the whole leaf but it reduces the stress and strain by about 95%,which proves that the model with vein has good ability to resist the wind load.Furthermore,the topological patterns of plant leaves under wind load are gained with the volume as the restrictive condition and the minimum flexibility as the target,and they are similar to those of the real leaves,which shows that the forming of leaf vein is a self-adaptive process in addition to achieving the physiological functions.