- 學位論文
應用新型非平表面於複合材料膠合接點之幾何開發與斷裂模式探討
Investigation of Geometrical Factors and Fracture Modes on Composite Bonded Joints using Non-Flat Interfaces
摘要
複合材料的應用已經相當廣泛，其優點主要在於材料重量輕且強度相當於一般的金屬材料。膠合法為連接複合材料結構的主要方法，然而，膠合法雖然優點眾多，該區域卻是整體結構最為脆弱之處，因此，提升膠合區域承受負載能力的議題成為了研究主題。本研究設計出非平表面幾何之複合材料單搭接接點，不僅結合文獻中多數學者使用的實驗與模擬印證方法，更把疲勞試驗中常見的裂紋分析引入靜態拉伸試驗中，透過高速攝影機觀察裂紋生長情形。本研究改變的非平表面幾何參數有：對稱排列、交錯排列、並排對稱排列、加強材材料、加強材直徑、對稱排列中心缺陷以及交錯排列中心缺陷，以一般平坦試片為對照組，再加入平坦試片中改變膠合區長度與中心缺陷組，印證非平表面試片極限負載提升之機制，尋找出最適合的非平表面幾何，實驗結果、模擬分析與裂紋傳遞之間有著良好的一致性。實驗結果顯示，交錯排列幾何中，C26IrD12試片相較於一般平坦試片最高可提升65%試片極限負載。本研究所提出之非平表面幾何製作方法，不需特別訂製新模具，因其方便性，有利於複合材料的相關產業中直接取用。
並列摘要
Nowadays, lightweight materials have been widely applied in many fields. Composite materials are one of lightweight materials frequently employed many industries. Because of their lightweight and strength characteristics, composite materials have gradually replaced metal materials. Adhesively bonded joints were a common way to combine composite structures which have inherent advantages over traditional mechanical joints. Thus, adhesively bonded joints are broadly used in structural applications and replaced traditional mechanical joints. In spite of the mentioned advantage, bonded area was the weakness area in the complete structure. Many studies had investigated the method to improve the joint strength. In this work, the reinforced materials were embedded in the glass-fiber composite lamina forming a non-flat geometry. Specimens were investigated experimentally, numerically. Cracks propagation were also observed by high speed camera and explained the mechanism of improvement of the joint strength. Seven different non-flat geometries were design in this study and compared to the traditional single lap joint. Two different geometries of flat interface confirmed the improved mechanism of joint strength of non-flat geometry. The experimental, simulation and crack propagation result are all in good agreement. Because of the convenience of the non-flat geometry invested in this study, the novel joint can be directly used in the related industries of composite materials.