长玻纤增强聚丙烯热塑性复合材料的制备、性能及应用

发布时间：2018-01-02 07:19

本文关键词：长玻纤增强聚丙烯热塑性复合材料的制备、性能及应用　出处：《湖南大学》2016年硕士论文　论文类型：学位论文

【摘要】：由于人类可利用能源及原材料的日益紧张,以及企业对汽车成本的控制越来越重视,使得复合材料作为车身轻量化的一个有效途径得到了越来越多的关注。长玻纤增强聚丙烯热塑性复合材料(LGF/PP)与传统的热固性树脂基复合材料相比因其成型周期短、可二次成型、易回收等优点正逐步引起不同国家及研究机构的关注。本文基于LGF/PP材料进行了深入研究,主要开展了以下工作:为改进热塑性复合材料成型过程中聚丙烯树脂对玻璃纤维的浸渍效果,提升最终制品力学性能,本文结合现有纯玻璃纤维针刺毡等单一纤维成网技术,开发出一种新型玻纤增强聚丙烯热塑性复合材料制毡工艺——立体混合干法制毡工艺。该方法结合无纺机械气流成网工艺,使毡材内部纤维之间形成相互交接的立体结构,不仅能保证聚丙烯纤维与玻璃纤维混合的均匀性,而且能大幅度减少玻璃纤维的损伤、断裂现象,有效地解决了增强材料与高粘度树脂熔融流动、浸渍成型困难的技术瓶颈,显著提升了玻纤增强热塑性板材的产品质量与力学性能。针对上述工艺所制LGF/PP复合材料的力学性能进行了相关分析研究。首先,基于力学拉伸实验验证了LGF/PP主要力学性能参数皆存在一定的分散性,其离散系数大小排列为:泊松比(6.11)失效应变(4.95)弹性模量(2.12)切变模量(1.97)。其次,针对该问题对LGF/PP基本力学参数进行了分散性分析,分析结果表明:该材料整体性能对失效应变及弹性模量具有较高的敏感度,而对泊松比及切变模量的敏感度较小,数据统计分析结果表明失效应变及弹性模量参数值服从正态分布。最后,探究了应变率对LGF/PP材料性能的影响,并依据其结果选用Cowper-Symonds材料本构模型对LGF/PP进行建模,对比仿真及实验结果,证明所采用的材料模型及参数可正确运用于LGF/PP复合材料上。参照现有电池包设计要求,考虑LGF/PP材料自身成型特点,完成LGF/PP电池包结构改进设计,使其对比于传统金属电池包在集成性、电磁屏蔽、绝缘与防水性、轻量化方面具有一定优势。基于力学压缩实验,验证电池包箱体主要设计参数内外倒角半径对其强度刚度的影响。完成金属材料及LGF/PP电池包静强度分析,结果表明:相比于传统金属材料电池包,LGF/PP电池包在质量上可减重80.97%,不同工况下的最大应力可分别降低56.55%、59.13%。
[Abstract]:Because humans can use energy and raw materials has become more and more serious, and more and more attention to the enterprise control the cost of the car, made of composite materials as an effective way of the lightweight body has got more and more attention. The long glass fiber reinforced polypropylene composites (LGF/ PP) and thermosetting resin matrix composite material compared to traditional because of its short molding cycle, two molding, easy recovery etc. are gradually caused by different countries and research institutions concerned. Based on the LGF/PP material are studied, mainly carried out the following work: for the soaking effect of polypropylene improved thermoplastic composite resin molding process of glass fiber, improvement in mechanical properties of final products the performance, combined with the existing pure single fiber glass fiber mat such as network technology, developed a new type of glass fiber reinforced polypropylene thermoplastic composite material felting process Solid mixed dry felting process. This method combined with airlaid nonwoven machinery technology, the three-dimensional structure of interactions formed between the fiber felt material, can not only ensure the polypropylene fiber and glass fiber mixing uniformity, and can greatly reduce the glass fiber damage, fracture phenomenon, effectively solve the reinforced material and high viscosity molten resin flow, the technical bottleneck of dip forming difficult, significantly enhance the quality of the products and the mechanical properties of glass fiber reinforced thermoplastic sheets. The mechanical properties according to the process of LGF/PP composites were investigated. Firstly, tensile experiments verify the parameters of the main mechanical properties of LGF/PP have certain dispersity based on the discrete coefficient size: Poisson's ratio (6.11) failure strain (4.95) elastic modulus and shear modulus (2.12) (1.97). Secondly, aiming at the problem of LGF/P P basic mechanical parameters of the dispersive analysis, analysis results show that the overall performance of the material has high failure strain and elastic modulus of sensitivity, sensitivity and less on Poisson's ratio and shear modulus, the results of statistical analysis indicate that the failure strain and elastic modulus parameters obeying normal distribution. Finally, explore the strain rate effect on the properties of LGF/PP materials, and on the basis of the results using the Cowper-Symonds material constitutive model of LGF/PP model, the results of simulation and experiments, it is proved that this material model and parameters can be correctly used in LGF/PP composites. With reference to the existing battery pack design requirements, considering the forming characteristics of LGF/PP material itself, complete the LGF/PP battery pack structure to improve the design, which compared to the traditional metal battery pack in integration, electromagnetic shielding, insulation and waterproof, has certain advantages of lightweight. Based on force Study of compression experiments validate the effect of battery pack box body of the main design parameters and fillet radius on the strength stiffness. Metal materials and LGF/PP battery pack static strength analysis, the result shows that: compared to the traditional metal materials of LGF/PP battery pack, battery pack in quality can be reduced 80.97%, the maximum stress can be reduced by 56.55% respectively under the condition of 59.13%.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U465.6

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