【作者】 龙霞；

【导师】 李兰友； 陈利；

【作者基本信息】 天津工业大学 ， 计算机应用技术， 2004， 硕士

【摘要】 本文主要介绍了在Windows环境下，利用Microsoft最新集成开发工具Visual C++．NET研制开发了应用于三维编织工艺设计的CAD系统。 首先在分析三维编织复合材料内部细观组织特性，即材料单胞内纤维束与基体在空间上的几何分布规律的基础上，建立了三维编织物的数学模型，为工艺设计提供理论基础。该单胞模型为一六面体形状，其取向平行于预制件的表面，且高为编织花节长。该模型中编织纱线具有椭圆形横截面，较已往圆形横截面的假设更接近于真实情况。经过对三维编织细观结构的拓扑分析，建立了编织工艺参数之间的关系，如编织角、编织花节长、纤维体积含量、复合材料的尺寸等。在此基础上，推导出三维编织工艺设计中用于排纱设计的数学公式，通过迭代法可以计算出主要的编织工艺参数。 该系统是应用于复合材料三维编织工艺设计阶段的专业性应用软件，采用面向对象技术编程，可在普通PC机上运行，不象以前的系统只能在特定的系统环境下运行。该系统采用Windows标准界面，运算速度快，用户接口友好，主要由文件子系统、绘图子系统和排纱设计子系统组成，实现了三维编织预制件的横截面的图形绘制、拾取、编辑、存储等功能，并可以实现工艺设计中的排纱设计。经实验验证，计算值和实验中的测量值吻合较好。该系统的研制，使三维编织工艺设计由计算机来实现，它使得工程技术人员不必把大量的精力耗费在繁琐的计算中，提高了设计的精度，加快了设计的速度，为提高三维编织工艺设计的质量做出了有意义的探索。更多还原

【Abstract】 A CAD system for 3D braiding process design has been developed in this thesis. The code has been wrote by using the latest assembled developing tools --Visual C+ +.Net, under the environment of the Microsoft Windows 2000.The mathematical model is defined for the process design on the basis of the microstructure of 3D braided composites. The defined unit cells have the brick shape which height is equal to the braiding pitch, and oriented in the same reference coordinate as the composites. The elliptical cross-section is assumed for the braiding yarn, which is more approximate to the realistic situation of the yarn in the composites. According to the topological analysis of the unit cells, the relationship between the braiding parameters is established, such as braiding angle, braiding pitch, fiber volume fraction, dimension of composites etc.. Based on the mathematical formulas, the mainly process design parameters can be calculated by the iterative method.The 3D braiding CAD system is the special application during the course of 3D braiding process design, developed by using the object-oriented technology. It runs on the PC, not like the old system that can only run on the special system environment. The system adopts the standard Windows user interface, has characters of computing fast, handling easily and friendly interface. It is made up of the file subsystem, the drawing subsystem and the process design subsystem on arranging yarns, it has realized the functions of drawing graph, picking graph, editing graph, saving graph and process designing. The c omputed d ata a pproximates t he e xperimental d ata. With t he research of the system, the process design of 3D braided preform is made totally by computer. The technicians are freed from the complex work, theprecision and speed of process design are enhanced, which contributes greatly to the design quality of 3D braided composites.更多还原