竹材作為自然材料，具備了生長快速、重量輕和易加工等優點，是優良的綠色建材。臺灣本土竹材廣為應用於工藝與傳統屋舍，然而國內目前尚無竹結構設計規範，故在現代建築之應用面受到限制。若欲引進國際竹構造規範ISO-22156(2021)，則需要相關試驗來探討其規定對本土竹材之適用性。本研究以此為前提，針對本土竹種刺竹進行竹桿挫屈試驗，搭配有限元素模擬，探討竹桿幾何性質對軸壓強度之影響，並與ISO設計公式和Ylinen公式比較，驗證前述公式之準確性，再根據分析與驗證結果提出公式之修正建議。
因竹材生長的有機性，天然竹桿取樣難以直接過濾單一幾何性質變因對於軸壓強度的影響，故本研究先進行竹材料基本試驗和竹桿挫屈試驗，並以Ansys對試體進行有限元素模擬，以基本試驗校正材料參數設定，再比較挫屈試驗與模擬結果，確保模擬的可行性，最後設定控制幾何性質之虛擬竹桿進行挫屈模擬，以探討各種幾何性質對於軸壓破壞強度之影響。
本文挫屈試驗竹桿試體之細長比介於0.6至3.0之間，大部分試體在竹節處發生挫屈破壞，推測與竹節纖維方向改變有關。竹桿軸壓強度與斷面積、慣性矩、軸向抗壓極限應力和軸向抗壓彈性模數呈現中度正相關，與細長比和弓形偏差率呈現中度負相關。與既有公式比較顯示ISO原設計公式對於竹桿軸壓強度之預測過於保守，平均強度比（試驗值/設計公式）達15.21，且低估強度的趨勢隨細長比增加而變大；Ylinen公式則有高估短桿強度，低估中長桿強度的趨勢。
虛擬竹桿的模擬結果顯示：
(1)錐度的影響：細長比和頂端管徑不變時，竹桿錐度越大則軸壓破壞強度越高，而ISO原設計公式對錐度較大的竹桿預測過於保守。
(2)弓形偏差率的影響：細長比不變時，竹桿弓形偏差率越大，軸壓強度越低，且最大弓形偏差位置越靠近頂端時軸壓強度越低，而虛擬竹桿強度下降趨勢與ISO原設計公式預測之下降趨勢差異甚大。
(3)邊界條件的影響：不同邊界束制條件的挫屈模擬結果顯示ISO原設計公式建議的有效長度係數K值偏保守。
(4)管徑大小的影響：不同管徑的竹桿，斷面積增加對強度增加的影響較慣性矩顯著，而細長比較大的竹桿在斷面積和慣性矩增加時強度上升較短桿顯著。
本研究提出軸壓破壞強度之修正公式，將平均強度比由15.21下降至6.88，大幅改善ISO原設計公式的保守程度，使竹結構的設計能更經濟並輕量化。

Being a natural material, bamboo is known for its short life period, light wight and is easy to machining. Although bamboo is widely used in traditional crafts and buildings in Taiwan, it is still ignored in modern architectural materials due to the lack of related legislation. If we try to introduce ISO-22156(2021) to Taiwan, which is the widely used standard of bamboo structures, we have to conduct related experiments for verification. This study carries out the buckling test of Bambusa stenostachya Hackel, conducts Finite Element Analysis, and compares it with the formula about axial compressive strength in ISO-22156 and Ylinen’s Formula, and put forward the modified suggestions.
It is difficult to separate the influence on axial compressive strength with a single variation because of bamboo geometric properties, so this study carries out the material and buckling tests first, and then conducts Finite Element Analysis by ANSYS to investigate the influence of bamboo geometric properties on axial compressive strength.
The results show that bamboo poles, which slenderness ratio are between 0.6 and 3.0, mainly occurred failure with buckling. The results also show axial compressive strength is moderately positive correlated with section area, moment of inertia, axial compressive ultimate stress, and axial compressive Young’s modulus, and moderately negative correlated with slenderness ratio and bow ratio. It also shows that the original ISO formula is too conservative, with the average strength ratio (experimental value/ISO formula compression capacity) up to 15.21. Ylinen’s Formula has the trend to overestimate the strength of short poles, and underestimate longer poles.
Simulated results of virtual bamboo poles show these points:
1. The axial compressive strength gets higher when the tamper of the bamboo pole is larger, and the original ISO formula calculates the compression capacity of larger tamper bamboo poles more conservatively.
2. Larger bow ratio bamboo poles have lower axial compressive strength, and also the maximum bow position near the bottom of the bamboo poles. The downtrend of strength between simulated results and the original ISO formula is largely different.
3. The simulation of different boundary conditions shows that the original ISO formula has a conservative value of the effective length coefficient.
4. Section area has a more significant influence on axial compressive strength than moment of inertia does. And bamboo poles with larger slenderness ratio have bigger upward trend than bamboo poles with smaller slenderness ratio when section area and moment of inertia get larger.
Recalculate the compression capacity with the modified suggestions of this study, the mean strength ratio decreases from 15.21 to 6.88. This study greatly improves the conservative degree of the ISO formula, and makes bamboo structures get lighter and more economical.

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