三维机织复合材料加筋板压缩性能研究

发布时间：2019-04-12 17:49

【摘要】：加筋板特有的结构形式能有效减轻结构重量和提高承载能力,被广泛应用于航空航天结构。三维机织复合材料加筋板采用连续纤维整体织造成型,具有传统层合复合材料加筋板所没有的独特优势:Z向纤维提高厚度方向刚度和强度,能有效抑制分层和改善连接区域性能。因此,对其压缩性能的研究具有重要的实用价值和工程意义。本文所研究的加筋板采用两种不同的机织结构:底板为浅交直联结构,筋条为正交三向结构,两者通过由筋条内引出的Z向纤维穿过底板连成一体。首先,研究三维机织加筋板预制件的机织工艺和内部细观结构,建立了四种不同结构形式的细观模型,包括浅交直联结构、浅交直联+法向纱结构、正交三向结构和“T型”连接结构,进行有限元分析得到各单胞的弹性性能,并研究了“T型”连接结构的Z向强度性能。然后,用四种单胞的集合重新构建加筋板,基于Hashin失效准则进行三维损伤扩展模拟,得到了加筋板的压缩性能。最后,采用树脂传递模塑成型工艺复合成型三维机织复合材料加筋板实验件,进行压缩实验研究其破坏机理。仿真结果与实验结果吻合较好,论证了本文所用研究方法的合理性和有效性。传统层合复合材料加筋板的主要失效模式为分层破坏或筋板间脱粘失效,本文所研究的三维机织复合材料加筋板,其底板与筋条的连接区域在压缩破坏过程中均不会发生分离,体现了其独特优势。底板与筋条的主要失效模式均为经向纤维压缩失效,底板的损伤从加载端两侧向中央扩展,最终导致了整体压缩破坏。本文的工作在机械结构力学及控制国家重点实验室完成。
[Abstract]:The special structure form of stiffened plate can effectively reduce the weight of the structure and improve the load-carrying capacity, so it is widely used in aerospace structures. The three-dimensional woven composite stiffened plate is woven by continuous fiber, which has the unique advantage of traditional laminated composite stiffened plate: Z-direction fiber increases the stiffness and strength of the thickness direction. It can effectively suppress the delamination and improve the performance of the connection area. Therefore, the study of its compression performance has important practical value and engineering significance. The stiffened plate studied in this paper adopts two different woven structures: the base plate is a shallow intersecting and direct structure, and the bar is an orthogonal three-way structure. The two are connected through the Z-direction fiber drawn from the bar through the floor. Firstly, the weaving process and internal meso-structure of the three-dimensional woven stiffened plate preform are studied, and four kinds of mesoscopic models are established, including the light cross direct structure, the shallow cross direct normal yarn structure, the structure of the three dimensional woven stiffened plate preform, and the internal meso-structure of the three-dimensional woven stiffened plate preform. The elastic properties of each cell are obtained by finite element analysis of the orthogonal three-way structure and the "T-type" connection structure. The Z-direction strength performance of the "T-type" connection structure is studied. Then, the stiffened plate is reconstructed from the set of four kinds of cells. Based on the Hashin failure criterion, the three-dimensional damage expansion simulation is carried out, and the compression performance of the stiffened plate is obtained. Finally, the three-dimensional woven reinforced composite plate was fabricated by resin transfer molding process, and the failure mechanism was studied by compression experiment. The simulation results are in good agreement with the experimental results, and the rationality and effectiveness of the research methods used in this paper are proved. The main failure modes of the traditional laminated composite stiffened plates are delamination failure or debonding failure between the stiffened plates. The three-dimensional woven composite stiffened plates studied in this paper do not separate the connecting regions between the bottom plate and the ribbons in the process of compression failure, and the main failure modes of the laminated composite stiffened plates are delamination failure or debonding failure. It embodies its unique advantages. The main failure modes of the bottom plate and the bar are the longitudinal fiber compression failure, and the damage of the bottom plate extends from both sides of the loading end to the center, which finally leads to the overall compression failure. The work of this paper is completed in the State key Laboratory of Mechanical structure Mechanics and Control.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33

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