三维机织物增强热塑性树脂复合材料的结构及力学性能研究

【作者】 王静；

【导师】 王瑞；

【作者基本信息】 天津工业大学 ， 纺织工程， 2004， 硕士

【摘要】 材料、能源、信息是现代科学技术的三大支柱。随着生产的发展和人们生活水平的提高，材料已从金属、无机非金属、高分子材料三大类发展到第四类——复合材料。由于全球结构用材料的消耗量日益增大，人类传统惯用的天然原材料资源逐渐短缺，所以复合材料应运而生。热塑复合材料，近几年研究较热。与热固性复合材料相比，虽然其树脂，特别是高性能的热塑性树脂的熔融粘度大，给树脂浸渍纤维带来了困难，但热塑性复合材料避免了热固性复合材料固有的环境适应性差、加工周期性长、难以回收等不足，并且具有较强的韧性和抗冲击性能、极好的抗破坏能力和阻尼性能及可循环利用等的特点。 利用简单织物(编织物、机织物、针织物、非织造布)与树脂复合制作层合板，是目前应用最广泛的纺织复合材料制作法，即分层固结与增强，所制得的材料为二维纺织复合材料，其不足之处是抗冲击性差，层间强度低，在承受弯曲应力或剪应力时，容易在层合处剥离或开裂。为克服二维织物复合材料层间强度低的缺点，人们研制开发了三维整体纺织复合材料。 本文采用微编纱作为三维织造的一种合适的中介媒体。研究表明用微编方法加工的微编纱，在后续加工过程中，能有效地保护增强纤维，而且它能满足均匀快速浸渍，苛刻的三维立体织造条件，这为三维织造和热塑复合材料的生产加工开辟了一条新的途径。同时，本课题对微编纱的加工工艺、结构参数的选定和微编纱的结构形态也进行了说明、分析和表征。 本课题主要研究了三维机织物的结构，还建立了三维机织物单元体的结构模型。织物的结构模型是通过对织物断面的观察及以下基本假设而建立的：假设织物由接结纱、经纱、纬纱和填充纱组成；纱线截面呈跑道形；接结纱和经纱由直线段和弧线段组成，纬纱、填充纱是直线，从而建立了三维机织物单元体的结构模型。在此基础上计算了微单元中的纱线长度、接结纱、经纱取向角及纤维体积分数，并将纤维体积分数的理论计算值与测试结果进行了比较，两者吻合较好，这表明本研究建立的三维机织物结构模型是正确的。 本研究还探讨了三维机织物的织造参数及织造过程，并总结和讨论了织造过程中出现的问题及解决的办法。 摘要 在模塑成型的复合固化中，本文采用了三个方案复合出几种试样，并对试样的成型温度，成型压力的确定给予了探讨，同时分析了成型压力与成型厚度之间的关系。 本文还主要对三维机织热塑性复合材料基本力学性能中的拉伸性能和弯曲性能进行了测试和研究，同时，对标志复合质量好坏的复合材料空隙率也进行了测定。通过对试制材料的拉伸性能值(拉伸强度、拉伸弹性模量)、弯曲性能值(弯曲强度、弯曲弹性模量)和复合材料空隙率的测试，分析和探讨了影响复合材料拉伸应力一应变曲线，弯曲载荷一位移曲线及基本力学性能的因素。研究结果表明，三维机织热塑复合材料预型件的结构(纱线的直径、三维机织物的结构)、预型件的预拉伸工艺(经纱和接结经的伸直程度)、复合成型工艺(成型压力)及复合材料空隙率，都对复合材料的力学性能有着一定的影响。在此基础上建立了三维机织热塑复合材料的工艺一结构一性能之间的关系，为确定这种复合材料的合理生产工艺及提高复合质量提供了理论依据。更多还原

【Abstract】 There are three main stays of science and technology in modern times: Material, energy sources and information. With the development of productive force and the improvement of standard of living, the material is transiting from meta, inorganic compound and macromolecule to composites. The natural resources are becoming shortage because beings are consuming more structural materials, then the composite emerges now and then, thermoplastic composites have been studied a lot during the recent a few years. Compared with thermosetting plastics, the molten viscosity of thermoplastic resin, particularly high performance thermoplastic resin is high, which creates difficulty in impregnation into fiber bundles, but, thermoplastic composites offer a number of important advantages over thermosetting plastics, such as unlimited shelf-life, better toughness/damage tolerance, high recycle ability, chemical and environmental resistance, etc.Using simply fabric(woven, braided fabric, knitted fabric, non-woven fabric) to be combined with resin to make laminated plate is the most widely used to manufacture textile composites at present, i.e. interlaminar binding and reinforcing strength, what is made is two-dimensional textile composite. However, these composites exhibited poor impact resistance, interlaminar shear strength, when they are bent and shorn, the phenomenon of delamination occurs. In order to conquer the poor interlaminar shear strength shortcoming of two-dimensional textile composites,3D whole textile composites are developed.In this paper, micro-braided yarn is taken as the medium, the study show that the core-spun yarn made by micro-braiding technology , and the reinforcing fiber can be protected effectively in the following process, and the yarn can get good impregnation, at the same time micro-braided yarn meet for the requirement of rapid, uniform impregnation and harsh 3D cubic weaving condition, this opens up new prospect for weaving of 3D and producing of thermoplastic composites. And, the process technique, the structure as well as the determination of structuralparameters for micro-braided yarn are illustrated and analysed in this article.This article mainly studies the structure of 3D woven, and the unit cell model of 3D woven structure is established in this paper. By means of observing the section of 3D woven and assuming micro-braided yarn section as racetrack shape, yarn configurations as an assemblage of linear and arc sections for binders and warps, and straight form for stuffers and wefts, the unit cell model of 3D woven structure is established in this study. On the basis of the model mentioned above, the length of constituent yarns inside the cell and the orientation angle of binders and warps as well as the fiber volume fraction are calculated. The calculated fiber volume fraction is compared with test results from selected samples of 3D woven composites .A good agreement is demonstrated between the theoretic predictions and the experiment results, this indicates that the unit cell model of 3D woven structure established above is right. This thesis also discusses the process producing of the 3D weaving.Meanwhile, the study sums and talks about the problems of the weaving process as well, and find out the treatment to deal with them.During the process of the consolidation molding consolidation, this paper adopts three schemes to make a kind of samples, while it gives and studies the molding temperature as well as adopts the molding pressure, analyzing the relationship between the molding pressure and the molding thickness.In this paper, the tensile property and bending property among the basic mechanics performance of 3D woven are tested, furthermore, the composite void content indicating compound quality is determine. Through measuring the tensile performance value(tensile strength and tensile modulus), the bending value (flexural strength and flexural modulus)and the composite void content of the specimens, this article analyzes and discusses the factors which influence the更多还原