Bamboo culm is a natural material characterized by a graded structure of vascular bundles in the radial direction and a regular distribution of bamboo nodes in the axial direction. To investigate the adaptation of bamboo culm structure to its natural environment, the bamboo culm structure was analyzed using a vascular bundle identification model, complemented by mechanical simulations. The results showed a certain pattern in the macroscopic dimensional characteristics of bamboo from the base to the top: the outer diameter decreased linearly; the internode length initially increased before decreasing; the length-to-diameter ratio gradually increased; and the wall-to-cavity ratio initially decreased before increasing. In response to external forces, bamboo exhibited strong stability, which was attributed to the thin and hollow wall as well as parabolic distribution of bamboo nodes. Along the axial direction, vascular bundle numbers linearly decreased, while the ratio of fiber sheath tissue and the distribution frequency of vascular bundles increased from the base to the top. In the radial direction, the length and area of vascular bundles tended to increase before decreasing, while the width tended to increase, leading to a decreasing length-to-width ratio. Overall, the radial variation pattern of vascular bundles showed nonsignificant variations at different heights.

中文翻译：

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利用计算机视觉和机械模拟分析竹秆的结构

竹秆是一种天然材料，其特征是维管束在径向上呈分级结构，竹节在轴向上呈规则分布。为了研究竹秆结构对其自然环境的适应性，利用维管束识别模型对竹秆结构进行了分析，并辅以力学模拟。结果表明，竹子的宏观尺寸特征从基部到顶部呈现一定的规律：外径呈线性减小；节间长度先增大后减小；长径比逐渐增大；壁腔比先减小后增大。在应对外力时，竹子表现出很强的稳定性，这归因于竹子壁薄且空心以及竹节的抛物线分布。沿轴向，维管束数量从基部到顶部呈线性减少，而纤维鞘组织比例和维管束分布频率增加。径向上，维管束的长度和面积呈先增大后减小的趋势，而宽度呈先增大的趋势，导致长宽比减小。总体而言，维管束的径向变化模式在不同高度表现出不显着的变化。