第六章 結論
6.1 結果比較
將非線性分析之實驗數據、理論解及數值模擬三者進行比較，
依據試體之厚度不同分別表示於圖 6.1 及圖 6.2 中。
圖6.1 厚度 2mm 之蜂窩重複單元實驗、理論及數值比較
圖6.2 厚度 3mm 之蜂窩重複單元實驗、理論及數值比較
由圖6.1 及圖 6.2 可發現，數值模擬及理論解之結果非常接近，
其中數值模擬是將實驗中之實際參數代入有限元軟體LS-Dyna 中所 得到之數據，而理論解之部分則是將實驗之參數代入式(28)中便可 得到，實驗數據之部分在校正過儀器之誤差後，可發現其與數值模 擬及理論解之結果也相當接近。而由以上三者之比對可知，考慮軸 向力影響之理論解會非常貼近真實情形，這也應證了軸向力對蜂窩 結構有其不可被忽略之影響。在數值模擬中厚試片之臨界值相較於 實驗值高了不少，而加上0.5%的瑕疵後可發現其臨界值有明顯下 降，由此可知厚試片對於瑕疵非常敏感。
6.2 結論
本研究以一個蜂窩結構的重複單元體來求解其非線性彈性性質，
分析蜂窩結構在受壓縮時，勁度產生變化的情形，得到其有效巨觀勁 度的理論解。在有些邊界條件下，理論解需藉由試誤法求得其值。結 果顯示，巨觀等效彈性係數比值會隨著外力的增加而降低，不同的厚 長比，有不同的非線性表現，對於薄壁蜂窩結構，厚長比低於 0.1 時，
基本上其巨觀等效彈性係數比與外力比成一線性關係。由數值結果可 知，蜂窩結構的強度受瑕疵與邊界的影響甚劇。
就蜂窩平面內挫屈的部份，實驗、理論與數值皆指出：不論幾 何尺寸、邊界條件，其初始挫屈模態皆為 Z-型挫屈，雖僅在實驗中 短暫的出現，並且很快的消失在大變形或其他挫屈模態中，但該型 挫屈確為蜂窩側向破壞的關鍵型式，值得好好研究。
參考文獻
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National Conference on Theoretical and Applied Mechanics, Tainan.
俞肇球（2013）二維蜂巢結構之橫向 Z-型挫屈，The 37th National Conference on Theoretical and Applied Mechanics, Tainan.
張儀婷（2006）含圓形微構件蜂巢材料力學性質之數值分析，國立成 功大學土木工程學系碩士論文。
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