臺灣博碩士論文加值系統

本文主要探討含15o傾斜角橢圓孔編織複合材料平板之破壞強度，利用有限元素分析軟體ANSYS及點應力準則進行預估。首先將裁切好碳纖維編織布浸入樹脂與丁酮混合液中進行含浸，利用加熱加壓的方式製成編織複合材料平板。隨後使用拉伸試驗機進行實驗值之拉伸破壞測試，再將已破壞之試片利用鑽石切割機沿紗束方向裁切樣本，進行包埋後置於金相顯微鏡下觀察其試片內部，並看到紗束波動、裂紋及脫層等畫面，進而瞭解內部破壞模式。
利用ANSYS及點應力準則對複合材料平板進行拉伸分析，把拉伸之破壞強度實驗值代入ANSYS軟體裡，進而求得其特徵長度及繪製孔洞與特徵長度之函數關係曲線圖，利用最小平方法建立其乘幕公式，最後求得破壞強度預估值，把預估值和實驗值做比較，所得的誤差在3.49%以內。因此可得知其研究方法能準確預估開橢圓孔試片之破壞強度。

In this paper, we mainly investigate the failure strength of braided composite plates each with an elliptical hole of 15o inclining angle. The Finite Element Analysis software ANSYS and the point stress criterion are used to predict the notched strength. First, we put the carbon fiber braid into the mixed liquid with epoxy resin, and then use hot-press method to make braided composite plates. Next, we use the tensile testing machine to obtain the experimental data and employ the diamond cutter to cut a sample along the direction of fiber yarn weaving. Then, we observe fracture mechanism by putting the sample under the metallographic microscope. Finally, we can see the fluctuating of yarn weaving together with crack and delamination.
By ANSYS and point stress criterion, the characteristic length and notched strength can be predicted. By comparison to experimental data, it is shown that our method can accurately predict the notched strength of braided composite plates with a maximum error of only 3.49%.

摘要 i
Abstract ii
目 錄 iii
圖目錄 vi
表目錄 x
第一章 前言 1
1.1引言 1
1.2文獻回顧 4
1.3研究動機 7
第二章 相關理論 8
2.1編織物複合材料性質的運算 8
2.1.1單位格子 9
2.1.2混合法則 10
2.1.3三維座標轉換 12
2.1.4勁度矩陣平均法 16
2.1.5纖維體積含有率的量測 18
2.2點應力破壞準則 19
2.3利用有限元素之點應力破壞準則預測開孔試片破壞強度 23
第三章 實驗 25
3.1實驗材料 25
3.2實驗設備 29
3.3實驗流程 30
3.4研究流程 40
3.5開孔平板 41
3.6拉伸試驗 42
3.7金相實驗 43
3.8整體研究流程圖 44
3.9金相流程圖 45
第四章 有限元素軟體分析 46
4.1有限元素分析軟體(ANSYS)介紹 46
4.2有限元素分析軟體(ANSYS)架構與分析流程 47
4.2.1前處理 47
4.2.2求解器 50
4.2.3後處理 52
4.3ANSYS整體分析架構流程圖 54
第五章 結果與討論 55
5.1未開孔試片及開孔試片破壞強度實驗值 55
5.2破壞模式 56
5.2.1巨觀破壞模式 56
5.2.2微觀破壞模式 57
5.2.3試片內部破壞情形 59
5.3特徵長度 60
5.4開孔試片強度預估 62
第六章 結論 64
參考文獻 65

1.Photo by 冠昇資訊科技有限公司

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20.Photo by more.Para Blaze CX iphone 6 4.7版碳纖維保護背殼