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1、南京航空航天大学 硕士学位论文 热固性树脂基纤维增强复合材料固化变形研究 姓名：朱凌宇 申请学位级别：硕士 专业：工程力学 指导教师：周储伟 2010-12 南京航空航天大学硕士学位论文 i 摘摘 要要 热固性树脂基纤维增强复合材料结构的固化成型经历了先升温后降温的变化过程,由于纤 维相和基体相热胀系数不同， 以及树脂基体的固化收缩， 结构内部会产生残余应力,若结构设计 不当会导致复合材料结构出模后翘曲变形。本文研究了影响热固性树脂基纤维增强复合材料固 化变形的因素，探寻了减小固化变形的方法。文章分为三个部分： 第一部分： 设计并制备三种（玻纤/环氧单向、正交和短切纤维复合材料）复合材料试验件
2、，测量了试 验件成型出模后的固化变形；对试验件进行静力拉伸、压缩实验，得到基本材料的力学参数； 分别提出了上述三种复合材料固化变形的理论模型，用试验结果验证了理论模型的可靠性。 第二部分： 建立了单向复合材料和正交复合材料的细观有限元模型，讨论了细观单胞的周期性边界条 件，计算了两种复合材料的固化变形和失配应力；利用单胞模型计算所得的热膨胀系数预测了 非对称层合板的弯曲变形。 第三部分： 针对一种复合材料桨叶结构，建立了有限元模型，利用上述研究成果模拟了桨叶的固化弯 曲变形，分析桨叶固化变形的影响因素从组份材料性能、结构设计两个方面提出了减小桨叶固 化变形的方案。 关键字关键字：热固复合材料；
3、固化变形；残余应力；细观有限元 本文的研究工作得到了国家自然科学基金项目(10772078，10472045)的资助。 热固性树脂基纤维增强复合材料固化变形研究 ii Abstract Thermosetting Resin matrix fibre-reinforced composites will experience heating-up and cool down variety in curing process. The mismatch of thermal and curing shrinkage between reinforced fiber and polymer ma
4、trix will introduce residual stresses in composites. Improper structure or ply-up design will lead to dimensional change and warpage of composite work piece. In this thesis，factors affecting warpage of composites were studied, also methods to reduce this warpage were explored. This thesis is divided
5、 into three parts. In part one, three sorts composite lamina specimen, i.e. glass fiber/epoxy unidirectional composite, tabby composite and chopped fiber composite, were designed and made. Their curing deformations were measured. Static tension and compression experiments were carried out to determi
6、ne their material parameters, e.g. stiffness of components and fiber volume fraction. The theoretical curing deformation prediction models for these three composites were suggested and they are verified by the experimental measurements. In part two, micro unit cell finite element models of unidirect
7、ional composite and orthogonal ply-up composite were built and the periodic boundary condition applied on them was specified. The curing deformation and micro scale residual stresses were calculated with these models. By adopting the thermal expansion ratio of the individual lamina obtained from the
8、 unit cell models, The warpages of asymmetrically plied laminates were forecasted. In part three, a finite element model of a typical composite blade was established. The thermal expansion parameters obtained in the chapters prior to were used to calculate the curing warpage of the blade. Factors af
9、fecting curing deformation of blade were studied. The suggestions to reduce curing warpage of blade by adjusting constitutional material and structure design were proposed. Key words: thermal setting composite; Curing deformation; residual stress; micro finite element 南京航空航天大学硕士学位论文 v 图表清单图表清单 图 2.1
10、 对称铺层的模具.7 图 2.2 固化温度为 130的单向带在模具中隆起.7 图 2.3 非对称铺层的模具尺寸.8 图 2.4 成型温度为 130的非对称层合板试件的弯曲变形.8 图 2.5 单向带横向拉伸强度试验件的破坏.13 图 2.6 单向带纵向压缩强度试验件的破坏.13 图 4.1 单向带横截面的微观结构.22 图 4.2 单向带微观单胞模型.22 图 4.3 正交布层合板微观单胞模型.23 图 4.4 周期性单胞示意图.24 图 4.5 微观单胞周期性边界条件.25 图 4.6 纤维体积百分含量为 65%单向带单胞最大主应力云纹图.28 图 4.7 纤维体积百分含量为 80%的单向带单胞最大主应力云纹图.28 图 4.8 单向带三个方向的热膨胀系数随纤维体积分数变化图.28 图 4.9 纤维体积分数为 40%的正交布层合板单胞模型最大主应力云纹图.30 图 4.10 纤维体积分数为 60%的正交布层合板单胞模型最大主应力云纹图.30 图 4.11 正交布的热膨胀系数随纤维体积分数变化图.30 图 4.12 02/0/90非对称层合板从 130降到 25的变形.32 图 4.13 02/45/-45非对称层合板从 85降到 25的变形.32 图 5.1 桨叶的有限元模型.35 图 5.2 桨叶的典型截面.35 图 5.3
