失效模式對於複合材料輕航機墜撞模擬之影響

輕型航空器的發展與需求日漸增加，複合材料的應用比例也呈上升狀態，適墜性的考量也需要受到重視。複合材料在航空界的應用逐漸取代傳統的金屬材料，但複合材料與金屬材料兩者特性上有許多的差異，無法以傳統的金屬材料的失效分析來判斷複合材料飛機結構的安全性，因此辨別複合材料在使用上的安全性是重要的研究方向。本研究將使用Zenith公司的STOL CH701 的機身作為研究的目標物，利用Pro/E建立3D模型，搭配有限元素分析軟體Abaqus 分析單一纖維方向碳纖維複合材料與多層碳纖維複合材料，考慮失效與未考慮失效參數進行分析。模擬之邊界條件為依據ASTM 規範的1.3VS0墜撞速度與AGATE所訂定的30o墜撞角度，使用Abaqus/Explicit建立動態墜撞模擬以能量輸出做為數據合理性判斷依據。本研究依據Hashin Failure Criteria 四種失效判斷公式，討論複合材料機身考慮材料失效參數，以5種不同墜撞速度下之材料失效進行比較。在低速9 m/s，複合材料機身無失效。當速度提高，複合材料疊層中沒有0o纖維之複材機身，受墜撞衝擊力影響，無0o纖維承受主要撞擊力，則由基體材料承受導致基體產生壓縮失效。包含0o纖維材料下，多層碳纖維材料在受到撞擊後主要由纖維承受撞擊力，造成纖維壓縮失效，基體則無失效。

關鍵字

有限元素法；輕航機； Hashin Criteria ；複合材料

並列摘要

The development and demand for light aircrafts is increasing day by day, and the proportion of composite materials used is also on the rise. The consideration of the crashworthiness needs to be taken seriously. The application of composite materials in the aviation industry gradually replaces traditional metal materials. However, there are many differences in the properties of both composite materials and metal materials. It is impossible to judge the safety of composite aircraft structures by the failure analysis of traditional metal materials. The safety of composites is the important field to research. This study will use the fuselage used by the company's STOL CH701 Light Sport Aircraft as the target of the study, using Pro/E to build a 3D model, with finite element analysis software Abaqus to analyze single fiber directions. Carbon fiber composite materials and multilayer carbon fiber composite materials are considered for failure and failure parameters are not considered. The boundary conditions of the simulation are based on the ASTM specification's 1.3Vs0 crash speed and the AGATE defined 30o crash angle, using Abaqus/Explicit to establish a dynamic crash simulation based on energy output as a basis for judging the rationality of the data. Based on the four kinds of failure judgment formulas of Hashin Failure Criteria, this study discusses the material failure parameters of composite materials and compares the material failures at five different crash speeds. At a low speed of 9 m/s, the composite body has no failure. When the speed is increased, the composite fuselage without 0o fiber in the composite laminate, which is affected by the impact of the crash. Because the fuselage has no 0o fiber to receive the main impact force, the matrix material will receive the impact force cause matrix to produce compression failure. With 0o fiber material, the multilayer carbon fiber material is mainly subjected to impact force after impact, resulting in fiber compression failure and no failure of the matrix.