适用于变形机翼的大变形高负载柔性机构设计方法研究

Morphing wings are requred in future advanced aircraft in terms of high aerodynamic property and low fuel oil consumption. Compliant mechanism of realizing curve deformation depending on topological structure and material elastic deformation, which not only achieve continuous smooth curve deformation of airfoil section and possess advantage of biological deformation, but also are light and activated easily, are ideal way of realizing morphing aircraft in future. But the design of compliant mechanism is confronted with developing bottleneck in aspect of large deformation and high load. The methods of designing compliant mechanism based on homogenizing material and linear or nonlinear can't break through the bottleneck.This project propose that the designing method of morphing compliant mechanism in large deformation and high load is searched by builing mechanics modeling of anisotropic composite material. Moreover, it is given priority to with theoretical analysis and secondary to with theoretical analysis.Topologic optimization model and solving method based on large deformation compliant mechanism of composite material are achieved.In the terms of bionic layer ,quadratic optimization method of supporting loads is built.The design method of large deformation and high load compliant mechanism in single variable stiffness or multistage metamorphic mechanism is realized by topological structure of large deformation and investigation of metamorphic mechanism using the concept of couple hardness with softness and experiment. According to the aerodynamic date of wing section, morphing wings are designed, simulated, tested and verified. This method provide the theory and technology foundation of morphing wing in future.

高气动性与低燃油消耗要求未来先进飞机具有可变形机翼。而依靠单体拓扑结构弹性变形的柔性机构，具有生物形变特征的优势能够实现翼型曲线的连续光滑变形，且质轻易驱动控制，是未来变形翼最理想的实现途径。但目前柔性机构设计面临着大变形与高负载发展的瓶颈，建立在均质化材料和线性或几何非线性设计基础上的柔性机构设计方法则无法突破这一瓶颈。本项目拟以理论分析为主，辅以仿生与实验研究，从符合未来机翼发展趋势具有各向异性的复合材料力学模型入手，探索大变形、高负载下形变柔性机构的设计方法。建立基于复材大变形柔性机构的拓扑优化模型及求解方法，借助仿生铺层，提出高负载的二次优化方法；在此基础上，借助生物"刚柔并济"的大变形负载结构拓扑和变胞机理研究，结合实验，建立适合大变形高负载的多级变胞柔性机构的设计方法；基于某翼型气动数据，进行变形翼的设计、仿真及实验验证。为未来飞行器变形翼设计提供设计理论与技术基础。

基于形变柔性机构的可变形机翼是未来飞机实现高气动性与低油耗最优途径和研究热点。针对目前形变柔性机构设计面临大变形与高负载的瓶颈，本项目从复合材料、多点驱动及多相材料、柔性变胞机构、刚-柔偶合机构以及有限元-无网格耦合方法等多途径进行了探索研究：.利用复合材料各向异性及可设计特性，建立了复合材料大变形形变柔性机构拓扑优化理论和设计方法；揭示了纤维方向（路径）对柔性机构变形及承载的影响机理；通过复合材料的纤维方向优化，有效提高了柔性机构的变形能力和降低局部应力；在此基础之上，发展了一种柔性机构复合材料与拓扑构型一体化设计与加工制造方法，设计了复合材料柔性机翼前、后缘，并进行了实验验证。.通过复杂设计域、多点驱动及多相材料下的大变形形变柔性机构拓扑优化设计方法研究：提出了针对不规则设计域的隐式函数表示方法及有限元混合离散的柔性机构设计方法；提出了驱动载荷位置与柔性机构拓扑的嵌套优化策略，建立了多点式驱动柔性机构的拓扑优化模型设计方法；建立了多相材料柔性机构的拓扑优化模型及设计方法。研究表明：该方法能合理地解决柔性机构大变形中柔性与刚性的矛盾，满足变形翼前、后缘大变形设计要求。.将变胞机构和柔性结构相结合，提出通过构件合并的变胞方法来提高结构的整体刚度，并以此合并点作为设计变量，建立了基于变胞的柔性机构设计方法；研究了不同数目的支撑位置对机翼承载的性能影响；实验验证了该方法有效解决变形翼前、后缘承载能力低的问题。.通过在大变形或几何形状复杂或需要较高计算精度的区域应用无网格方法，在位移边界及其他区域应用有限元方法，建立了基于有限元-无网格耦合的拓扑优化方法；研究了不同耦合方法对拓扑优化中数值问题的影响，并在减少了计算量、几何形状复杂性和大变形问题显示出很大优势。.本项目研究工作为国内首次开展变形翼技术研发奠定理论基础，有力推动了本项目组与中航多家顶尖企业合作，并在工信部立项启动研究工作。