【作者】 王东；

【导师】 孙东立；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2010， 硕士

【摘要】 碳纤维/环氧树脂复合材料以其高比强度和高弹性模量、可设计性强、抗疲劳断裂性能好、耐腐蚀、结构尺寸稳定性好以及便于大面积整体成型的独特优点,已经在航空、航天等领域广泛应用。热压罐-铺层技术是现阶段航空、航天复合材料构件的主要成型方法,但使用该技术对航天领域大型复杂结构舱段进行整体成型的相关工艺研究很少。本文则针对这些问题,进行了较为深入的研究。碳纤维/环氧树脂复合材料舱段由碳纤维增强材料和树脂基体两部分组成。在本课题的研究中,选取T700 12K碳纤维和T300 1K碳布作为增强材料,使用616环氧树脂和AG-80环氧树脂作为树脂体系的基体树脂。复合材料舱段整体成型工艺主要包括树脂胶配制工艺、碳纤维预浸料制备工艺、舱段铺层工艺、整体成型工艺和固化工艺等组成,本文重点对其中的树脂改性、固化制度、铺层设计等相关问题进行研究。本文研究了热塑性树脂PEK-C对616环氧树脂和AG-80环氧树脂体系的改性效果,制备了环氧树脂基体浇铸体并对其性能进行了测试。结果表明经改性后的树脂体系具有优异的耐高温性能,其力学性能能够满足设计要求,可以用于高性能复合舱段的成型。运用树脂体系T-β图外推法和固化动力学原理近似获得复合材料舱段的固化制度,使用该固化制度按国家标准制备相应的性能试样,并进行试验检测。使用经典层合板理论对舱段的力学性能进行了计算,通过对舱段性能实测值和计算值的对比分析,表明经典层合板理论可以对整体的力学性能进行预测,为整体舱段的铺层工艺设计提供参考依据,同时也验证了该固化制度对舱段固化成型的适用性。硅橡胶软膜材料在高温条件下具有良好的热膨胀性能,能够在舱段固化过程中为舱段内型面、犄角等不易加压的部位提供压力,使舱段固化的表观尺寸可以达到使用要求。本文对硅橡胶线膨胀系数和体积膨胀系数关系进行了推导,得到硅橡胶加热条件下尺寸和对舱段压力与温度变化的关系。根据整体舱段结构特点设计了舱段的成型工艺。把舱段分为蒙皮、大端框、小端框、纵向筋、环向筋、窗口等六个部分,蒙皮分为外蒙皮和内蒙皮两部分使用单向碳纤维预浸料分两次铺层成型,大端框、小端框、纵向筋和环向筋将碳布预浸料分别在专用模具中铺层成型,然后将各部分在模具中整体进行组装、贴硅橡胶、制作真空袋;最后,舱段在热压罐中真空加热加压进行固化。更多还原

【Abstract】 Carbon fiber reinforced epoxy resin matrix composites have good performance in specific strength, elastic modulus, corrosion resistance, dimension stability, fatigue resistance, and molding, therefore, they have been widely used in the field of aerospace. Nowadays autoclave-overlay technology is the main molding method to fabricate composite components applied in aerospace. However, the application of this technology in the integrated molding process of large and complex cylinder is lack of study in this paper integrated molding operation of carbon fiber reinforced epoxy resin matrix composite is studied.The cabin made of carbon fiber refined epoxy resin matrix composite is consisted of carbon fiber reinforcement and resin matrix. In this paper, according to the selection principle and the demand of use, carbon fiber of T700 12K and carbon fiber cloth of T300 1K were employed as reinforcement, and 616 and AG-80 epoxy resin were selected as matrix materials. The integrated molding processes of carbon fiber reinforced polymer matrix composites include cabin resin system preparation process, carbon fiber prepreg technology, cabin overlay technology, integrated molding technology, curing process, etc. This paper focuses on the research of the selection of resin system, curing system and the overlaying direction.The modifying effects of PEK-C, a thermoplastic resin, on the 616 and AG-80 epoxy resin system were studied by the preparation of the epoxy resin matrix using injection method and its properties were analyzed. The results show that the modified resin system has excellent heat resistance, good mechanical properties, and it can be used as matrix resin for the production of high-performance composite cabin.The curing system for the composite was obtained from the extrapolation of T-βdiagram of resin and the principle of curing kinetics. According to national standards, the samples used for property testing were fabricated by the selected curing system. The mechanical properties of the cabin were both tested by experiments and calculated through typical laminated plate theory. The comparison results indicate that the laminated plate theory can well forecast the mechanical properties of the cabin and can provide guidance to the design of the integrated molding process of the cabin.Silicone rubber thermal expansion material possesses an excellent thermal expansion property. It can supply enough pressure for the inner contour and corners of the cabin to form during the curing process, and make its final dimension satisfy the demand of utilization. In this paper, through the derivation of the linear and cubic expansion coefficients, the relationship between the dimension of the silicone rubber when heating, and the cabin pressure and temperature were achieved. This result provides good reference to the use of silicone rubber on the curing of the overall cabin.The molding process was designed according to the structural features of the overall cabin. First the cabin was divided into six parts including skin, large end frame, small end frame, vertical stiffener, circular stiffener and window. The skin, consisted of outer skin and inner skin, was molded with prepreg of unidirectional carbon fiber by two passes. The other four parts were formed respectively with prepreg of carbon fiber cloth in special molding dies. Then each part was assembled integrally in dies and pasted silicone rubber. After vacuum bag was made, according the selected curing system, the cabin was cursed in the vacuum autoclave under certain temperature and pressure.更多还原