Finite element modelling of complex movements during self-sealing of ring incisions in leaves of Delosperma cooperi
Finite element modelling of complex movements during self-sealing of ring incisions in leaves of Delosperma cooperi
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DOI：
10.1016/j.jtbi.2018.08.023
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发表时间：
2018-12-07
影响因子：
2
通讯作者：
Speck, Olga
中科院分区：
文献类型：
--
作者：
Klein, Hartmut;Hesse, Linnea;Speck, Olga
建立了一个数值计算模型，以描述受损伤的Delosperma cooperi叶片复杂的自封闭机制。为此，叶解剖结构被简化为由五个同心组织层组成的模型。具体参数（弹性模量、渗透率、孔隙度等）分配给每种组织类型，用于模拟其物理特性。这些参数是从活的植物材料或从文献中实验确定的。所开发的计算机模型认为，叶作为一个充满液体的多孔体内的连续体的方法，以确定控制方程。伤口的建模考虑了外周组织的损伤和切口引起的游离表面。水通过这些自由表面的损失启动了自密封过程。它进一步表明，组织的渗透性和反射系数（溶质的细胞膜的相对渗透性）是自密封过程的决定性参数，而弹性模量的影响可以忽略不计。因此，自密封机构是导致叶片的局部（切口区域）和全局（整个叶片）收缩的液压驱动过程。模拟结果与自然植物叶片上的实验结果进行了比较，验证了模拟的自密封过程的准确性。研究结果将为开发具有自密封功能的新型生物启发技术产品提供有价值的投入。(C)2018爱思唯尔有限公司版权所有
A numerical computer model was developed in order to describe the complex self-sealing mechanism of injured Delosperma cooperi leaves. For this purpose, the leaf anatomy was simplified to a model consisting of five concentric tissue layers. Specific parameters (modulus of elasticity, permeability, porosity, etc.) were assigned to each tissue type for modelling its physical properties. These parameters were either determined experimentally from living plant material or taken from literature. The developed computer model considers the leaf as a liquid-filled porous body within a continuum approach in order to determine the governing equations. The modelling of the wound accounts for both the injury of peripheral tissues and the free surfaces caused by the incision. The loss of water through these free surfaces initiates the self-sealing process. It is further shown that the tissue permeability and the reflection coefficient (relative permeability of a cell membrane for solutes) are the determining parameters of the self-sealing process, whereas the modulus of elasticity has a negligible influence. Thus, the self-sealing mechanism is a hydraulically driven process which leads to a local (incision region) and global (total leaf) contraction of the leaf. The accuracy of the modelled self-sealing process was validated by comparing simulation results with experiments conducted on natural plant leaves. The results will serve as valuable input for developing novel, bio-inspired technical products with self-sealing function. (C) 2018 Elsevier Ltd. All rights reserved.