【作者】 卢敏；

【导师】 周来水；

【作者基本信息】 南京航空航天大学 ， 机械工程， 2011， 博士

【摘要】 在飞机上大量使用复合材料是航空业未来发展的必然趋势，而实现这一转变的制造技术之一是先进的纤维束自动铺放成型。它在发达国家已广泛应用于大型航空航天复合材料构件的制备，而在国内的相关研究尚处于起步阶段。CAD/CAM技术与材料技术、成型装备是实现自动铺放的三大要素。其中，CAD/CAM技术是重要基础，在充分掌握其工艺原理的条件下，对其进行先行的研究与探索是十分必要的。在CAD/CAM技术中，预定路径的规划与设计又是实现自动铺放的关键技术之一。将其作为课题进行深入研究，对我国研制具有自主知识产权的高性能纤维铺放设备具有重要的意义。本文综合铺丝工艺、成型构件和各种铺放条件，并抽象为数学模型，借助经典微分几何理论与向量代数方法，建立路径曲线方程，进而将路径轨迹的求解问题转化为常微分方程的迭代计算问题，利用它精确地表述路径生成与变化所遵循的基本规律。论文的主要研究成果如下：1.研究分析了铺丝工艺、曲面外形以及路径规划之间的制约关系。讨论了复合材料自动铺放设计的一般原则；从几何角度分析了曲面多层铺放的几何变化及其对铺放的影响，提出了铺丝工艺要求下的曲面铺放曲率的极值问题；分析并确定了曲面与路径轨迹的数学描述方法。2.在总结前人研究成果的基础上，对基准路径的生成作了深入研究。针对各种外形的典型构件，分别改进和提出了截平面法、线面相交法、投影法、插值映射法等多种算法，并编写程序以验证其正确性。3.开展了路径轨迹在曲面上的密化与覆盖方法研究。基于铺放工艺特点提出了精确的等距偏移密化算法和快速的近似等距偏移密化算法；基于构件加载后的内部应力特征提出了插值均分密化算法。对于偏移密化过程中出现的边界问题和缝隙填补也给出了统一的求解算法。4.提出了多层铺放的路径轨迹生成算法。构件的最终成型是纤维束连续多层、多角度铺放完成的。本文研究了偏置曲面上曲线的相关问题，在此基础上结合相关层合板的铺放特征将上述基准路径与密化覆盖方法推广至多层曲面，为实现构件的多层铺放提供了必需的算法基础。5.以各种典型成型构件为研究对象，将前文的研究成果与具体的实例结合，提出了具体的解决方法，并编写程序进行仿真与验证。更多还原

【Abstract】 With the development of aviation industry, one of the certain trends is the extensive use ofcomposite materials on aircraft, and the automatic fiber placement (AFP) is one of the determinationsto acechieve this transition. In developed countries, many large components are manufactured on AFPmachines, and the correlative technology is in the initial stage in China. The fundamental elements ofAFP are CAD/CAM technology, material and processing equipment. And as the importanttechmology in CAD/CAM, predetermined path planning and design is deeply researched in thisthesis.Basd on differential geometry theory and vector algebra, the mathematic models and path equationsare induced under various placement conditions. So path trajectory is solved by iterative calculation ofordinary differential equations, and the rule of path generation and varity is revealed at the same time.Achievements on this thesis are described as follows.[1] The constraint is analzed among fiber placement rules, surface shape and path planning.First, the general principle of composite structure design is analyzed. Then thegeometric change of mould surface with continuous multi-layer placement is studied,and the curvature extremum is proposed first time correspond to fiber placement rules.Finally, mathematical expression method is studied and determined for mould surfaceand path trajectory.[2] Based on preliminary work, the initial path generation methods are developed. Aim tovarious typical components, several methods are proposed such as section, intersectionof straight line and surface, line projection, fitting and mapping, and so on. Everyalgorithm is verfied with experiment.[3] It is researched that the path trajectories are continuously offset and covered on mouldsurface. The exact and approximate path offset methods are both proposed for differentplacement conditions. And another different equidistant path generation method isproposed for explicit stress distribution. In addition, path extension on surfaceboundary and path filling on fiber gap are solved with uniform treatments.[4] The path generation method for multi-layer fiber placement is developped andextended. Since the finished components are manufactured by multi-layer fiberplacement, the path algorithm ought to comprise offset surfaces. First, curves on theoffset surfaces are analyzed, then the corresponding algorithms of initial path andoffset path generation for multi-layer placement are developped according to thelaminated plate.[5] Algorithms are applied to several typical components. The various simulations areproposed to verify the path generation algorithms.更多还原