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1、南京航空航天大学硕士学位论文联结翼复合材料机翼结构优化设计与重量特性分析姓名：乔巍申请学位级别：硕士专业：飞行器设计指导教师：姚卫星20090101南京航空航天大学硕士学位论文 I 摘 要 联结翼布局飞机可以被定义为由上反角的后掠前翼和下反角的前掠后翼联结在一起形成菱形框架结构的飞机。作为一种飞行器创新布局，联结翼飞机具有较轻的重量、较高的刚度、较小的诱导阻力和较大的升力系数等优点，是兼顾气动性能和结构效率折衷方案的一种较佳的布局型式。 联结翼机翼结构由于前后翼存在耦合作用，使结构的优化设计变得比较复杂。目前对于联结翼的研究，探讨与总体布局相关的工作较多，而对结构细节设计方面的研究较少，且大多
2、是金属结构，复合材料结构很少。本文采用分步实现的优化策略，进行了在多种工况和不同约束条件下联结翼复合材料机翼结构优化设计，探讨了刚度分配和有关参数对于机翼结构重量的影响。 本文提出分步实现的优化策略。首先，在应力、应变和位移约束下，以结构重量最轻为目标，进行优化设计，确定蒙皮的铺层尺寸；第二步：优化设计梁的缘条和长桁的尺寸，使整个机翼结构既满足强度和刚度要求，又满足稳定性要求。 采用分步优化设计的策略，分别研究了联结板高度、联结刚度、许用翼尖扭转角、稳定性以及蒙皮0度层方向角对结构重量的影响。 关键词：联结翼，复合材料结构，结构优化，分步优化，重量特性 联结翼复合材料机翼结构优化设计与重量特性
3、分析 II Abstract The Joined-wing aircraft maybe defined as an aircraft that incorporates tandem wings to form diamond shapes, in which forewing is aft swept with positive-dihedral angle and rear-wing is forward swept with negative-dihedral angle. As an innovative aircraft configuration, Joined-wing ha
4、s many advantages, such as lighter weight, higher stiffness, lower induced drag and bigger lift coefficient. It is a better configuration both in aerodynamics and structure than traditional configuration. The composite structure of joined-wing is intricate for optimal design because of the coupling
5、between the forewing and rear-wing. The work of joined-wing concentrated more on layout and metal materials, and less on the details of structural design and composite materials. A two-step optimization technology was proposed in this thesis to achieve the analysis and design, in which 16 load cases
6、 and different constrains were included. The effects of the stiffness distribution and the joint parameters on structural weight were investigated systematically. Firstly, the thickness of composite laminates was optimized in the proposed two-step optimization technology, in which the structural wei
7、ght was taken as the objective function, and stress、strain and displacement constrains were included. Then the dimensions of the stringer and beam stip were optimized. So both stiffness and buckling constraint were considered. Based on the two-step optimization technology, the effects of joint heigh
8、t, joint stiffness, torsion angle of wing tip, buckling and composite angle on structural weight were also investigated in this thesis. Keywords: joined-wing, composite materials, structural optimization, two-step optimization technology, weight properties 南京航空航天大学硕士学位论文 V 图表清单 图1.1 典型的联结翼布局飞机. 1 图1
9、.2 联结翼结构四杆模型. 4 图1.3 联结翼与悬臂翼的前后翼弯矩. 4 图2.1 层合板应力应变示意图. 7 图2.2 等强度最优设计法的优化原理示意图. 10 图2.3 MSC.Nastran的结构优化设计流程图.11 图2.4 复合材料平板结构示意图. 12 图2.5 复合材料平板结构有限元模型. 12 图2.6平板结构重量迭代历程图. 14 图2.7 平板主应变云图. 15 图2.8 平板次应变云图. 15 图2.9 平板剪应变云图. 15 图3.1 联结翼空间菱形框架结构. 17 图3.2 气动载荷的分解. 17 图3.3 机翼材料分布对比示意图. 18 图3.4 联结翼机翼剖面. 18 图3.5 不同联结位置的相对重量. 21 图3.6 前翼结构示意图. 21 图3.7 后翼结构示意图. 22 图3.8 机翼主要受力构件示意图. 24 图3.9 梁
