臺灣博碩士論文加值系統

當一個具有均勻橫截面的產品承受拉伸或壓縮時，應力通常會在產品上均勻分佈。然而，如孔洞、尖角、缺口或瑕疵等突然變化可能會造成應力集中，使局部應力急劇上升，造成材料容易破壞。這些應力集中的現象對於工程設計成敗至關重要，因為它們可能損害零件的結構完整性，導致疲勞、裂縫和最終失效。大多數現有研究集中於單個或多個圓形孔洞對應力分佈影響，但未探討在零件上加入不同形狀、排列和孔洞間距的影響。因此研究旨探討塑膠零件上的孔洞設計對應力分佈的影響，主要研究是減少應力集中以增強零件的強度和耐用性。研究使用田口法結合灰關聯分析來進行多目標優化，考量應力、應變及應力集中係數等多個品質目標。首先，以田口法設置四因子三水準之條件後，繪製拉伸試驗棒，並於試驗棒中間分別開設輔助孔洞的各種因子與水準（如直徑、寬度、孔洞之間距離及數量）並進行Ansys軟體分析。通過Ansys分析軟體進行數值分析，並計算其對應的應力集中係數。最後，使用灰關聯分析整合實驗數據，評估不同設計參數組合的優劣，並通過實際拉伸試驗驗證理論結果。研究結果顯示，最佳參數組合為A3 B2 C1 D3，其孔洞數量對應力分佈和應變行為的影響最顯著，其次為孔洞間距離，再來為孔洞直徑，寬度影響最小，因此可由孔洞設計上的調整，從而提高零件的整體強度和耐久性。

When a product with a uniform cross-section is under tension or compression, the stress is typically evenly distributed. However, sudden changes such as holes, sharp corners, notches, or defects can cause stress concentration. This can lead to a significant increase in local stress, making the material prone to damage. Stress concentrations are crucial in engineering designs as they can compromise the structural integrity of a part, leading to fatigue, cracking, and eventually failure. Most existing studies focus on the effect of single or multiple circular holes on stress distribution and do not explore the impact of adding different shapes, arrangements, and hole spacing to the part. Therefore, the research aims to explore the impact of hole design on plastic parts on stress distribution. The main goal is to reduce stress concentration to enhance the strength and durability of parts. The study uses the Taguchi method combined with gray correlation analysis to perform multi-objective optimization, considering multiple quality objectives such as stress, strain, and stress concentration coefficient. Initially, the conditions of four factors and three levels are set using the Taguchi method, and then a tensile test rod is drawn. Various factors and levels of auxiliary holes (such as diameter, width, distance, and number between holes) are opened in the middle of the test rod and carried out. Numerical analysis is performed through Ansys analysis software, and the corresponding stress concentration coefficient is calculated. Finally, Grey Relational Analysis is used to integrate the experimental data, evaluate the advantages and disadvantages of different design parameter combinations, and verify the theoretical results through actual tensile tests. The research results show that the best parameter combination is A3 B2 C1 D3. The number of holes has the most significant impact on stress distribution and strain behavior, followed by the distance between holes, then the hole diameter, and the width has the smallest effect. This means that it can be adjusted through hole design, thereby improving the overall strength and durability of the part.

摘要................... i
Abstract................... ii
誌謝................... iv
目錄................... v
表目錄................... vi
圖目錄................... vii
第一章、緒論................... 1
1.1背景................... 1
1.2文獻回顧................... 1
1.3動機與目的................... 3
1.4 論文架構................... 3
第二章、基礎理論................... 5
2.1應力集中................... 5
2.2田口法................... 9
2.3灰色關聯分析................... 12
2.4應力-應變曲線................... 15
第三章、實驗方法與步驟................... 17
3.1實驗流程................... 17
3.2田口法實驗參數設計................... 19
3.3 Ansys 軟體分析邊界設定................... 20
3.4輔助孔洞直徑................... 22
第四章、結果與討論................... 26
4.1田口法試驗................... 26
4.1.1方案Ⅰ-固定位移之田口拉伸實驗結果................... 26
4.1.2方案Ⅱ-固定施力之田口拉伸實驗結果................... 30
4.2灰色關聯性................... 34
4.2.1方案Ⅰ-固定位移之灰色關聯性結果................... 34
4.2.2方案Ⅱ-固定施力位移之灰色關聯性結果................... 35
4.3拉伸試驗結果及分析................... 36
4.4拉伸試驗結果及分析與理論驗證................... 38
4.5小結................... 40
第五章、結論與未來展望................... 41
5.1結論................... 41
5.2未來展望................... 41
參考文獻................... 42
附錄A................... 44
Extended Abstract................... 46

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