【作者】 杜希岩；

【导师】 李炜；

【作者基本信息】 东华大学 ， 纺织工程， 2007， 硕士

【摘要】 复合材料夹层结构的研究和应用迄今已有50多年的历史，凭借其较高的强度和刚度、较轻的质量，近年来被广泛应用于航空航天、舰船及民用等各个行业。而经编轴向织物则是一种无屈曲的增强织物，其最大的特点是承力纱线在织物中是伸直平行的，它有利于充分发挥纤维的性能，大大提高了其复合材料制品的力学性能、抗疲劳性能和抗损伤容限性能，提高了复合材料的可设计性和可混编性。随着对经编轴向增强织物研究的深入以及复合材料成型工艺的发展，经编轴向织物增强夹层结构复合材料开始在游艇、风力发电等领域得到应用。本课题首先详细地研究了夹层结构复合材料的制备工艺，包括增强织物、芯层及树脂体系的选择，成型工艺的优化，树脂体系配方和工艺参数的确定。在芯层结构复合材料加工工艺的试验中，重点讨论了不同的PVC芯材加工方法对于树脂流动性能的影响，并确定出了最佳的芯材加工方法。在此基础上，讨论了一种新型的夹层结构复合材料成型加工用的内置导流布工艺。本文测试了经编轴向织物增强夹层结构复合材料试样的弯曲和压缩性能，并对织物克重、铺层方向、毛毡、芯层厚度、成型工艺等因素对夹层结构复合材料弯曲和压缩性能的影响进行了分析，并且利用声发射检测的手段，讨论分析了材料的破坏形式。最后，在实验室工作的基础上，采用真空辅助树脂转移成型工艺成功地制作了长7米、宽2米的夹层结构复合材料风机机罩。本文通过实验，分析了增强体及芯材的相关参数对夹层结构复合材料力学性能的影响，讨论了制作过程中存在的问题，实际制作了复合材料制件，对夹芯复合材料的应用以及为企业选择合理的工艺方法提供了一定的指导意义。更多还原

【Abstract】 The composites sandwich structures have been studied for over 50 years. It has been widely used in aerospace, marine and civil departments due to its lightweight and high stiffness. Multi-axial warp knitted fabrics are a kind of non-crimp reinforcements. Yarns in the reinforcements are straight to bear load. The strength of the yarns can be got fully used in composites, which gives good mechanical property, fatigue resistance and damage tolerance.With the investigation on multi-axial warp knitted fabrics and the composite molding technology, the multi-axial reinforced composite sandwich is getting applied in yacht, wind blade etc.This paper discussed the composite sandwich molding process. It included the selection of reinforcements, core materials and resin system. The molding process was optimized. The component ratio of resin and technical parameters were settled down.During the composite sandwich molding process, much more attention was paid on various methods to prepare PVC core materials. The factors, which significantly influence the flow front of the resin, were discussed. The reasonable method for preparing core materials was obtained. A new composite core molding process was introduced with an inlaid distribution media.The bending and compression properties of the composite sandwich panels were tested. The influence of the fabric area weight, lay-up angle, thickness of core material, the mat and molding processes have been discussed. With the help of AE test, the damage behavior of the sandwich structures was analyzed.Finally, a composite sandwich for nacelle cover of the wind turbine, 7mx2m, was successfully made by vacuum assistant resin transfer molding process.The influences of the reinforcements and core materials on the composite sandwich structures were discussed in the paper. The problems met during experiments were solved. The real practice was made in the work. It will be very helpful to guide the production of composite sandwich structures.更多还原