臺灣博碩士論文加值系統

在本篇研究中，是研究關於利用有限元素法分析之點應力準則，搭配實驗內容對含傾斜30度橢圓孔之編織複合材料試片進行開孔強度的探討。首先將碳纖維編織布含浸環氧樹脂後，用熱壓法製成複材試片。之後，編織複合材料試片會被製作成具有傾斜橢圓孔的拉伸試樣，最後利用拉伸試驗機進行測試，得到開孔強度的數據。用有限元素分析軟體ANSYS計算開孔試片之特徵長度，再用最小平方法建立特徵長度和橢圓孔半徑的函數關係圖。最後可以得到每組試樣的預測開孔強度。從預測值和實驗值進行兩相比較，可以發現實驗值和預測值相近，計算結果發現，預測值與實驗值之誤差在3.84%內。因此，由本研究的分析方法得出結論，基於有限元素分析法之點應力準則可以準確的預測出具中心傾斜橢圓孔編織複合材料試片的開孔強度。

In this study, we used both Finite Element Based Point Stress Criterion (FEBPSC) and experiments to investigate the notched strengths of braided composite laminates each with an inclined elliptical hole of inclined angle 30o. First, carbon braided fabrics were reinforced with epoxy resin to make composite plates by hot-press method. Then,braided composite plates were made into tensile specimens each with an central inclined elliptical hole. Tensile tests were applied to the specimen to obtain their notched strengths. The finite element analysis based point stress criterion was used to calculate the characteristic length for each specimen. Least-squares method is adopted to set up a functional relationship between the characteristic lengths and the elliptical hole radii. Finally the predicted notched strength for each specimen can be obtained. According to the comparison results the predicted notched strengths were well matched with the experimental notched strengths for all specimens. The maximum error for all specimen between the predicted notched strengths and the experimental notched strengths is only within 3.84%. Therefore it can be concluded that the finite element analysis based point stress criterion is very effective to predict the notched strengths of braided composite plates each with an central inclined elliptical hole.

致謝 i
摘要 ii
Abstract iii
目錄 v
圖目錄 viii
表目錄 xi
第一章 前言 1
1.1 引言 1
1.2 文獻回顧 4
1.3 研究動機 6
1.4 章節概要 7
第二章 相關理論 8
2.1點應力準則 8
2.2編織物複合材料的工程材料性質計算 10
2.2.1 單位格子 11
2.2.2單方向紗束工程模數計算12
2.2.3 三維座標轉換 13
2.2.4勁度矩陣平均法 17
2.3纖維體積含有率量測 18
2.4利用有限元素分析法之點應力準則預測開孔強度 19
第三章 實驗 21
3.1實驗材料 21
3.2實驗儀器 22
3.3試片製作流程 22
3.4平板開孔加工 30
3.5拉伸實驗 31
3.6金相實驗 32
3.7研究流程 33
第四章 有限元素軟體分析 35
4.1 有限元素軟體ANSYS介紹 35
4.2　ANSYS軟體分析架構 36
4.3 ANSYS分析之流程 37
第五章 結果與討論 41
5.1 編織複合材料平板的破壞模式 41
5.1.1 巨觀破壞模式 41
5.1.2 微觀破壞模式 42
5.2 孔洞半徑與特徵長度之關係 44
5.3 實驗組之強度預估 46
5.4 驗證組之強度預測 47
第六章 結論 48
參考文獻 49
附錄一52

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