【作者】 杨建灵；

【导师】 张丽艳；

【作者基本信息】 南京航空航天大学 ， 航空宇航制造工程， 2013， 博士

【摘要】 桨叶结构设计是直升机设计中的重要内容，其性能的优劣对直升机有着重要的影响。长期以来，由于复合材料桨叶内部结构复杂，桨叶结构设计一直是在以剖面描述为中心的原准设计体系下开展和实施的。这种设计方式在过去数十年中发挥了重要作用，然而随着直升机技术的发展，这种设计方式逐步暴露出设计效率低、难以精确和直观表达出桨叶的真实三维内部结构以及忽视桨叶设计与制造之间的内在联系等问题。这一系列固有缺陷决定了以剖面描述为中心的桨叶结构原准设计体系已难以适应当前以数字化样机和MBD（Model Based Definition，基于模型定义）为技术特征的直升机数字化研制体系的需要。为此，本论文提出了以全三维描述为中心的复合材料桨叶全组件整体参数化定义方法，并以此为基础系统而深入地开展了复合材料桨叶结构自动三维几何建模、剖面特性与整体特性计算、桨叶结构的优化设计以及整个设计过程的集成，自主研发了BSDS（Blade Structure Digital Design Integration System）复合材料桨叶结构数字化设计集成系统平台，形成了一种新的基于整体参数化定义的桨叶结构设计模式，并提供了该模式下从几何建模、结构特性计算、结构参数优化到设计过程集成的一整套方法。论文主要的研究内容和创新点概括如下：1.根据直升机复合材料桨叶各组件的几何外形特点及其构成，并综合考虑以数字化样机和MBD为技术特征的产品数字化研制体系的需要，提出了精确反映桨叶组件真实结构外形的整体参数化定义方法。针对桨叶结构中最为复杂的复合材料蒙皮结构，归纳出四大类共十二种子类的蒙皮铺层类型，通过铺层的整体定义和分层定义相结合的方式实现了桨叶蒙皮的参数化定义；对其他组件也依据其结构几何特点制定了相应的整体参数化定义方法。该方法不仅实现了桨叶各类型组件几何外形的整体参数化描述，而且在几何外形参数化定义的基础上引入了诸如铺设顺序、材料类型以及铺放角度等桨叶分析、制造信息，提出了一套较为完整的复合材料桨叶全组件数据结构表达机制，使其不但能够便捷地提供桨叶几何建模及桨叶结构分析所需数据，还能为桨叶制造提供相关数据信息。研发了智能向导的桨叶组件定义模块，引导工程设计人员以简便直观的交互方式实现对各组件的定义。桨叶组件的整体参数化定义方法是本文整个研究工作的基石。2.提出并实现了一种复合材料桨叶结构的自动化几何建模方法。该方法以本文提出的整体参数化定义方法为基础，通过对桨叶各组件结构特点的总结与归纳，并综合应用B-Rep（Boundary Representation，边界表示法）实体数据结构、NURBS（Non-Uniform Rational B-Spline，非均匀有理B样条）曲面体系、曲面等距、曲面裁剪等几何造型理论及方法，以参数驱动的方式，自动高效地建立复合材料桨叶结构的三维几何外形。针对复合材料蒙皮组件，提出了蒙皮外形分片逐次构造方法和由上一铺层内表面构造当前蒙皮铺层的算法来实现其几何外形的自动构建；针对桨叶其他组件，根据组件参数化定义方法的不同，提出多区段结合式和整体成形式两种不同的几何建模方法。本文提出的桨叶结构自动化几何建模方法是首次系统地对直升机复合材料桨叶结构的三维几何外形建模进行的研究。该自动化建模方法显著提高了桨叶建模的效率，有效地增强了桨叶结构数字化设计的能力，也为基于三维模型定义的数字化制造奠定了基础。3.提出了一种基于整体参数化组件定义及建模的桨叶结构特性分析方法。该方法适应于桨叶组件的整体参数化定义方法带来的改变，以桨叶剖面特性和整片桨叶结构特性计算为核心内容，分别根据桨叶各剖面和整片桨叶结构特性的定义及物理意义，推导得出相应的计算公式。针对桨叶结构特性分析中的重点及难点——剖面扭转刚度计算，提出了铺层块假设以及长厚比的概念，并基于闭口薄壁梁理论，给出了复合材料桨叶剖面扭转刚度的高效计算方法；对于整片桨叶结构特性，则是在剖面质量线密度和剖面重心分布符合分段线性连续假设的基础上，推导出了相应的计算公式。开发了基于整体参数化组件定义且与桨叶结构自动化三维建模无缝集成的桨叶结构特性分析软件模块，实现了桨叶结构特性参数的自动计算，通过实例验证表明该方法可行、有效。4.提出了一种基于整体参数化定义的复合材料桨叶结构优化设计方法。该方法是建立在桨叶组件的整体参数化定义方法、桨叶结构的自动化三维几何建模及其结构特性分析方法的基础上，通过对桨叶结构设计问题的分解，将其抽象并转化为剖面优化设计问题和整体优化设计问题。剖面优化设计是通过桨叶结构剖面参数进行优化得出桨叶结构整体优化设计初值的过程。整体优化设计则是通过对桨叶整体结构参数的调整来实现桨叶结构优化的设计过程。该方法不同于以往基于抽象的简化模型所开展的桨叶优化设计研究，其优化设计的参数直接来源于桨叶结构的整体定义参数，优化结果能够直接反映到真实的三维桨叶组件结构上，并且能够对没有参考样机数据的桨叶进行创新结构设计，得出优化的设计方案。方法的有效性和优势通过实际桨叶结构优化设计实验得到了认证。5.提出了一种桨叶结构的数字化设计集成系统的总体方案，构建了一个基于Web的复合材料桨叶结构数字化设计集成系统平台（BSDS）。不同于已有桨叶结构设计所采用的原准设计、校核、交互设计修改、再校核、再修改的设计流程，本论文提出的设计流程以数字化设计为导向，通过对桨叶结构设计的各环节进行数字化改造，有效整合各流程间的输入、输出关系，提供可拖选、可重构、所见即所得的流程建模方式，不仅能够建立起类似于原有桨叶结构设计的常规顺序式设计流程，也可以根据具体设计任务建立起自动迭代式设计流程。通过对设计过程相关软件的集成，利用工作流引擎的驱动实现设计流程的自动运行。其优点是能够随着桨叶结构设计方法的改进，快速而高效地建立起相应的设计流程，能够通过自动迭代式设计流程的建立提高整个桨叶结构设计的效率。更多还原

【Abstract】 Blade’s structure design is essential of helicopter design, and its performance greatly influencesthe helicopter. Blade structure design implemented in the prototype design system centered on sectiondescription, which has played an important role in the past few years and made great contribution tothe development of helicopter technology. But with the development of science and technology, someproblems of this design method gradually emerges, such as low efficiency, poor precision, difficulty inexpressing the real structure of blade, neglecting the internal relationship between the design andmanufacture of blade. These inherent defects indicate that the prototype design system focusing onsection description can not meet the need of helicopter digitized development system with technicalcharacteristics of the digitized prototype and MBD (model based definition). Therefore, the moduleparametric definition for composite rotor blade centered in full three-dimensional (3D) description isproposed in this paper. Based on this, several key technologies are further studied systematicly,including3D geometric automatic modeling, sectional and global characteristics calculation,optimization design for blade structure and design process integration. Besides, a new blade structuredesign model based on iinteger-oriented parametric definition has formed, and some approaches basedon this model, such as geometric modeling, structure characteristic computation, structure parameteroptimization and design process integration, are proposed in this paper. The main contents andinnovative points are summarized as follows:1. According to the geometric characteristics and compositions of helicopter composite blade, theinteger-oriented parametric definition which precisely reflects the real shape of blade structure is firstprovided after a comprehensive considering of the need of product digitized development system withtechnical characteristics of the digitized prototype and MBD. As regards the most complicatedcomposite skin structure in the blade, the paper concludes four main types and twelve subtypes ofblade skin ply, and the parametric definition of blade skin is implemented by combining the globaldefinition with the hierarchical definition of ply; Based on its structure geometric characteristics, theirglobal parametric definitions are made for other components. This method not only realizes the globalparametric description of blade structure, but also introduces blade analysis and manufacturesinformation, such as ply sequence, material types and ply orientation angle based on parametricdefinition. And it puts forward a comparatively complete expression mechanism of data structure forcomposite blade component, which not only provides the required data for blade geometric modeling and structure analysis but also for blade manufacture. The blade component definition module withintelligent guiding is developed to guide engineering designers to realize the component definition inconvenient interactive mode. Therefore, the global parametric definition of blade component is thefoundation of this paper’s research work.2. A geometric automatic modeling algorithm is put forward for composite blade structure. Basedon the proposed global parametric definition, the algorithm summarizes the structure characteristics ofblade components and comprehensively applies the geometric modeling theory and method includingB-Rep solid data structure, NURBS surface system, surface offset, surface trimming and so on. Andthen the3D shape of composite blade structure is constructed in parametric driving modeautomatically and effectively. According to the composite skin components, the slicing successiveconstruction method of blade skin shape is proposed, and the shape of the current skin ply isautomatically constructed by the last laminated inner surface; as for other blade components, twodifferent geometric modeling algorithms such as segmental combining and integral forming are putforward by the different parametric definition. The proposed blade automatic modeling algorithm isthe first systematic study of helicopter composite blade modeling. The blade modeling is significantlyimproved and the digital design for blade structure is effectively enhanced, which establish the basisfor digital manufacture based on3D model definition.3. A blade structural characteristics analysis method based on global parametric componentdefinition and modeling is proposed. It can be suitable for the change brought out the globalparametric definition of blade components. The calculations of blade sectional property and bladestructural characteristics are taken as the core, and their calculation formulas are respectively derivedfrom the corresponding definition and physical meaning. According to the emphasis and difficulty inblade structure characteristic analysis such as the sectional torsional stiffness calculation, the conceptsof ply block hypothesis and length to thickness are proposed, and the effective calculation ofcomposite blade sectional torsional stiffness is given by the theory of closed cross section thin-walledbeams; For the whole blade structural characteristic, its calculation formula is derived by assumingthe sectional quality linear density and sectional barycenter distribution are in accordance withpiecewise-linear continuity. The software module of blade structure characteristic analysis with globalparametric definition and seamless integration of blade automatic modeling is developed to realize theautomatic calculation of blade structure characteristic parameters. Experiments demonstrate that theproposed method is available and effective.4. The optimum design method based on global parametric component definition is put forward for composite blade structure. Based on the global parametric definition of blade components, theautomatic geometric modeling of blade structure and the analysis of blade structural characteristics,the blade structure design problem is decomposed to the sectional and global optimization designproblems. The former is the acquisition process of the initial values of blade structure globaloptimization by optimizing the sectional parameters extracted from global structure parameters. Thelatter is the design process of blade structure optimization by adjusting the blade global structureparameters. Different from the previous research on blade optimization design based on the abstractsimplified model, the optimization design parameters are directly from the global definitionparameters of blade structure, and the corresponding optimization results can be reflected on the realstructure of3D blade component. Therefore, it can effectively improve the efficiency and accuracy ofthe practical blade structure design process. The effectiveness and advantages of the proposed methodare confirmed by means of the practical optimization experiments of blade structure.5. The overall scheme of digital integrated system of blade structure design is presented, and thecorresponding platform based on Web is established. Different from the existing structure design flowof original-quasi design, check, interactive design and modification, recheck and re-amendment, theproposed design process is first taking digital design as a guide, and then the input and output of theprocesses are effectively integrated by the digital transformation for blade structure design to providethe process modeling method, which can be selected, reconstructed and WYSIWYG (what you see iswhat you get). This method establishes not only the conventional subsequent design process similar tothe origin blade structure design, but also the automatic iterative design process according to theconcrete design task. By integrating the design related software, the driven workflow engine is used torealize the automatic running of the design process. With the improvement of blade structure designmethod, the corresponding design process is rapidly and efficiently established. And it can improvethe design efficiency of global blade structure by establishing the automatic iterative design process.更多还原