【作者】 吴莉莉；

【导师】 姚卫星；

【作者基本信息】 南京航空航天大学 ， 飞行器设计， 2011， 硕士

【摘要】 在航空航天结构中,结构重量是重要的性能指标之一,减重可以提高飞行器的机动性和续航性,还可节约燃油。作为飞机结构的重要组成部分,翼面结构型式多样,加筋板结构已被广泛应用于各种翼面结构中,它的布局优化设计日益受到航空航天界的关注。布局优化本身就是优化设计的难点。对于复合材料翼面结构而言,设计变量多,不仅有结构的型式、筋条、梁、肋的个数、位置、尺寸,还有铺层厚度、铺层顺序等等,种类复杂,既有连续变量,又有离散变量;约束类型多样,这些都使得布局优化问题求解难度大。针对翼面结构的布局优化问题,本文提出了一种二级优化设计技术:第一级采用基于近似模型的优化方法实现布局和尺寸的综合优化,其优化思想为构建一个初始铺层确定的辅助层合板,将梁、肋、筋条的个数、位置、筋条型式、截面形状等作为布局设计变量进行试验设计,铺层厚度作为尺寸设计变量,各试验点对应的最轻重量作为响应值,根据试验点及响应值建立近似模型,利用多岛遗传算法优化求解结构最轻重量对应的最佳布局,然后对其进行尺寸优化得各铺层厚度,并计算出此时层合板的弯曲刚度系数;第二级铺层顺序优化,考虑层合板的制造和工艺约束,层合板各分层的厚度必须是单层材料厚度的整数倍,铺层角通常取一些标准的角度,各分层在层合板厚度方向上的相对位置可以任意变化。本级的思想是将铺层顺序优化等效为对铺层角度的整数规划问题,采用基于等效弯曲刚度的方法,以层合板的各铺层角作为设计变量,以层合板弯曲刚度系数与上一级优化所给最优弯曲刚度系数之间的误差最小为目标,应用多岛遗传算法,求出满足给定层合板铺层厚度和最优弯曲刚度要求的层合板最优铺层结构;最后在二级优化的基础上,通过协调稳定性约束,实现综合优化。本文利用上述方法,分别研究了复合材料加筋壁板和某型飞机水平安定面的布局优化问题,验证本文方法的有效性与实用性。更多还原

【Abstract】 Weight is an important performance index for aerospace structure. Weight reduction can not only improve the mobility and endurance capability of aircraft, but also save fuel. As a significant component of airplane structure, wing structure configuration types vary. Among them, stiffened plate structure has been widely used, and its layout optimization design is concerned increasingly in aviation realm.Layout optimization is a difficulty of design. For composite wing configuration, there are many design variables, including the type, the number of reinforced bars, beams and ribs, thickness and stacking sequence, etc, varying from continuous to discrete specie. Together with the various constraints, all of these make layout optimization problem difficult.In this paper a layout optimum design formation for wing configuration is proposed. This formation composed of three steps. Firstly parametric finite element model was set up and approximate model is used to construct the weight function of layout variables and size variables, and then to optimize the weight function to obtain the layout and size of the stiffened panel under given stacking sequence. Secondly the equivalent bending stiffness and GA were employed to deal with the ply stacking sequence optimization, where the requirements of manufacture and etc. were considered. And finally the buckling constrain results given by the layout optimization and stacking sequence optimization were collaboratively optimized and thus the optimal composite stiffened panel was determined.The layout optimization design of the composite stiffened plate and the horizontal stabilizer of certain airplane are studied in this paper using the above method. The method proposed in this paper is proved to be efficient and practical by comparing the final result with the initial solution.更多还原