【作者】 高峰；

【导师】 矫桂琼；

【作者基本信息】 西北工业大学 ， 工程力学， 2004， 硕士

【摘要】 对树脂基体复合材料采取层间颗粒增韧是提高复合材料层压板韧性、抗冲击能力和抗分层能力的有效途径，在保持原有复合材料湿热性能的前提下，通过层间颗粒增韧，还可以改善垂直纤维方向的强度、抗疲劳性能以及耐溶剂性，并不影响原有的成型工艺。因此层间颗粒增韧技术为复合材料在飞机主承力结构的应用提供了有力的技术支持。 本文采用层间颗粒增韧技术制备试验件，基于提高冲击后压缩强度（CAI）和考察损伤阻抗、损伤容限的目的，试验测试了Ⅱ型层间断裂韧性G_Ⅱc、准静压痕（QSI）试验的分层起始能量和接触力—凹坑深度关系。根据试验结果筛选了合适的增韧配方，并对损伤容限和损伤阻抗的表征参数进行了探讨。对增韧机理的分析表明，由增韧颗粒和基体树脂所形成的层间区具有良好的韧性及有效吸收断裂能量的微结构，因此，通过层间增韧可以显著提高复合材料的韧性并抑制分层的发生。对一些影响层间增韧效果的参数进行总结归纳，从被增韧体系、增韧颗粒和工艺三方面为层间颗粒增韧复合材料的实际工程应用和开发提供技术支持。本文的最后还借助于有限元方法对层间增韧复合材料进行了宏观和细观断裂韧性分析，基于Mori-Tanaka等效夹杂理论，计算了颗粒含量和尺寸对J积分的影响，有限元分析的结果同样表明层间增韧可以有效的降低裂纹尖端应力水平，并暗示界面是可能存在的失效原因，所进行的数值分析起到了进一步支持和解释增韧机理的作用。更多还原

【Abstract】 Toughening thermoset matrix composites with interlayered thermoplastic particles is an effective method to improve fracture toughness and impact resistance without sacrificing hot/wet properties. Furthermore, transverse strength, fatigue resistance and solvent resistance can also be enhanced. Drapability and tackness of interleaved prepreg is maintained as conventional level. Therefore, interlayer toughened composites are the excellent candidate materials for primary structure of aircrafts.In this paper, composites modified with particle-interlayer were fabricated. Based on the aims of improving compression strength after impact (CAI) and evaluate damage resistance and damage tolerance, Mode II fracture toughness test and quasi-static indentation test (QSI) were conducted. The optimum combination and damage parameters were determined according to experimental results. The toughening mechanisms reveal that interlayer zones, formed by thermoplastic particles and matrix, significantly suppress delamination and absorb amount of fracture energy. The parameters affecting toughening effects were also investigated, which is helpful for future engineering application. A Finite Element Analysis (FEA) was eventually conducted, using Mori-Tanaka model and J-integral, to further explain the toughening mechanisms and fracture behaviour of the particle interleaved composites. The aim of the analysis was to examine the influence of the particle concentration and size, and the interaction between the particle and the crack tip. FEA results indicate that interlayer zones can effectively lower J-integral and stress around the crack tip, and the high stress distribution in the region close to the interface can be the driving force for interfacial failure.更多还原