三维多层缠绕编织复合材料细观结构与力学性能研究

发布时间：2018-04-16 08:22

本文选题：三维编织 + 细观模型　；参考：《南京航空航天大学》2015年硕士论文

【摘要】：本文所研究的三维多层缠绕编织复合材料是一种新型的三维编织复合材料,其有着三维编织复合材料所共有的优点,同时又有着自身的独特优势,是一种值得深入研究的材料。本文主要从以下几个方面对其进行了研究。首先,编织工艺与纱线空间走向的研究,获得了三维多层缠绕编织复合材料在底盘上的投影路径,得到了纱线在空间的分布情况,直观地展现了三维多层缠绕编织复合材料的空间构型。进一步在编织工艺的基础上建立了三维多层缠绕编织复合材料单胞,获得了一些必要的参数,如纤维体积含量、编织角、纱线填充因子等。接着,利用刚度平均法证明了三维多层缠绕编织复合材料是一种正交各向异性材料,并用该方法和Kregers加权平均模型WAM分别求解其刚度性能,包括了独立的9个工程弹性常数。基于所建立的单胞模型,用有限元方法重新得到了三维多层缠绕编织复合材料的弹性常数,并与刚度平均法和WAM预测的弹性常数进行了对比,分析了两种理论解的优缺点。其次,利用Abaqus/Explicit进行显式动态分析,并通过用户自定义材料VUMAT子程序实现损伤单元的刚度折减。分别采用Mises准则和Puck准则判断基体和纤维材料的失效状态,模拟拉伸与压缩工况下的损伤过程,最终得到了三维多层缠绕编织复合材料的强度性能。最后,在实验室利用较为先进的RTM工艺复合成型三维多层缠绕编织复合材料,获得了低孔隙率、缺陷较少的试验件,并完成了其力学性能的测试,将实验结果和仿真结果对比,分析了误差原因,证明了本文所用研究方法的准确性。
[Abstract]:The three dimensional multilayer braided composites studied in this paper are a new type of three dimensional braided composites, which have the common advantages of three dimensional braided composites, and at the same time have their own unique advantages, and are worthy of further study.This article mainly carries on the research from the following several aspects.Firstly, the projection path of 3D multi-layer winding braided composite material on the chassis is obtained by studying the braiding process and yarn spatial trend, and the distribution of yarn in space is obtained.The spatial configuration of three-dimensional multi-layer winding braided composites is displayed intuitively.On the basis of braiding technology, the unit cell of 3D multilayer winding braided composites was established, and some necessary parameters were obtained, such as fiber volume content, braiding angle, yarn filling factor and so on.Then, the stiffness average method is used to prove that the 3D multilayer winding braided composite is an orthotropic material, and the stiffness performance is solved by using this method and the Kregers weighted average model (WAM), including nine independent engineering elastic constants.Based on the established unit cell model, the elastic constants of 3D multilayer winding braided composites are reobtained by finite element method, and compared with the stiffness averaging method and the elastic constants predicted by WAM, the advantages and disadvantages of the two theoretical solutions are analyzed.Secondly, the explicit dynamic analysis is carried out by using Abaqus/Explicit, and the stiffness reduction of the damage element is realized by the user-defined material VUMAT subroutine.Mises criterion and Puck criterion are used to judge the failure state of matrix and fiber material respectively, and the damage process under tensile and compression conditions is simulated. Finally, the strength properties of 3D multi-layer winding braided composites are obtained.Finally, three dimensional multilayer winding braided composites were formed by using advanced RTM process in laboratory. The low porosity and less defects were obtained, and the mechanical properties of the composites were tested and compared with the simulation results.The error causes are analyzed and the accuracy of the research method used in this paper is proved.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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