Modelling full-culm bamboo as a naturally varying functionally graded material
Modelling full-culm bamboo as a naturally varying functionally graded material
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DOI：
10.1007/s00226-020-01246-6
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发表时间：
2020-11
影响因子：
3.4
通讯作者：
Yusuf Akinbade;I. Nettleship;C. Papadopoulos;K. Harries
中科院分区：
文献类型：
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作者：
Yusuf Akinbade;I. Nettleship;C. Papadopoulos;K. Harries
竹的横向特性对竹的力学性能有很大影响，而横向特性不易通过实验测量。本研究开发了一个框架和计算工具，以评估竹子的材料和机械性能。建立了竹作为横向各向同性材料的径向梯度材料特性数值模型。介绍了随机场法作为一种量化竹子在其全秆状态力学特性方面的测量不确定度的方法。提出了四种日益复杂的竹模型周压试验方法：利用Castigliano定理进行理论评价；一种忽略茎壁梯度特性的正交各向异性模型并且，两个模型——一个离散模型和一个连续模型——定义了横向各向同性梯度材料。每个模型的输出与实验结果进行了比较、校准和验证。虽然所建立的模型是稳健的，但它们的应用已经引起了对基本假设的质疑，即竹的功能分级行为可以使用混合规则来捕获。
The mechanical behaviour of bamboo is greatly influenced by its transverse properties, which are not easily measured by experiment. This study develops a framework and the computational tools required to evaluate the material and mechanical properties of bamboo in its full-culm form. A numerical model of bamboo as a transversely isotropic material with functionally graded material properties in the radial direction is developed. The random field method was introduced as a means of quantifying the measured uncertainty of bamboo with respect to the mechanical characterisation of its full-culm state. Four increasingly complex approaches to model circumferential compression tests of bamboo are presented: a theoretical evaluation using Castigliano’s theorem; an orthotropic model neglecting the graded nature of the culm wall; and, two models—one discrete and one continuum-based that define a transversely isotropic graded material. Output from each model is compared, calibrated and validated with experimental results. While the models developed were robust, their application has drawn into question the fundamental hypothesis that the functionally graded behaviour of bamboo can be captured using the rule of mixtures.