Key message

Mechanical models of inosculations benefit from moderate geometric detail and characterisation of the structurally optimised area of interwoven tension-resistant fibres between the branches.

Abstract

Living architecture is formed by shaping and merging trees, often in combination with non-living technical elements. These structures often employ the mechanical and physiological adaptations of living trees to support structural loads. Designed and vernacular buildings utilise inosculations to redistribute forces, redirect growth, and provide redundancy. Mechanical models of inosculations in living architecture must be built according to the adaptations available to the tree. Here, mass allocation and fibre orientation are examined. Under typical gravity loads, a zone at the top of the inosculation is subject to tension. This is of particular interest because a trade-off in fibre orientation between mechanical and physiological optimisation is necessary. In tree forks, this results in specifically adapted interwoven fibres. In this study, Finite Element Analysis (FEA) is used to develop different mechanical models to fit bending experiments of four Salix alba inosculations, comparing the models’ accuracy in replicating rotations in the joint. Nine models were developed. Three levels of detail of mass allocation are considered for global isotropic (3 models) and orthotropic (3 models) mechanical properties as well as a model including the interwoven tension zone, a model of local branch and trunk orthotropy, and a model combining these two localised features. Results show significant accuracy gains come from moderate geometric accuracy and consideration of the tension-zone optimisation. The construction of the tension zone in FEA is simple and applicable to natural and artificially induced inosculations.

中文翻译：

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比较线弹性对吻合接头弯曲的结构模型

关键信息

结合的机械模型受益于适度的几何细节和分支之间交织的抗拉纤维结构优化区域的特征。

抽象的

生命建筑是通过塑造和合并树木而形成的，通常与非生命技术元素相结合。这些结构通常采用活树的机械和生理适应性来支撑结构载荷。设计和乡土建筑利用隔离来重新分配力量、重定向增长并提供冗余。必须根据树木可用的适应性来构建活体建筑中的机械模型。在这里，检查质量分配和纤维取向。在典型的重力载荷下，吻合顶部的区域会受到拉力。这是特别令人感兴趣的，因为在机械和生理优化之间的纤维取向的权衡是必要的。在树叉中，这会产生特别适应的交织纤维。在这项研究中，Salix alba接种，比较模型在关节中复制旋转的准确性。开发了九个模型。考虑了全局各向同性（3 个模型）和正交各向异性（3 个模型）力学特性的质量分配的三个层次细节，以及一个包括交织张力区的模型、一个局部分支和主干各向异性模型，以及一个结合这两者的模型本地化的特征。结果表明，适度的几何精度和对张力区优化的考虑带来了显着的精度提升。FEA 中张力区的构造简单，适用于自然和人工诱导的吻合。