基于力学近似模型的大展弦比机翼结构优化设计

发布时间：2018-03-13 18:00

本文选题：大展弦比机翼　切入点：近似模型　出处：《哈尔滨工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：机翼是飞机的重要组成部分。机翼结构设计目前普遍是基于历史设计案例,根据当前设计参数经过修改满足设计要求即完成,很少对设计进行调整和优化,使结构在满足刚强条件下更加轻质、可靠。本文主要以某大展弦比机翼为例,研究了机翼结构强度、刚度等重要指标的近似建模方法,并基于近似模型建立了机翼优化模型,设计了高效的优化算法,实现对机翼结构优化设计。针对某大展弦比机翼具体结构特点,结合飞机结构强度计算中的经验公式和材料力学中的相关理论建立了机翼力学近似解析模型,包括:机翼最大应力近似模型、机翼最大挠度近似模型和机翼翼肋扭转角近似模型。近似模型充分考虑了原有力学模型中没有涉及的翼梁位置、翼肋个数、分段式(内、外翼)机翼等设计变量,为机翼结构优化设计提供模型支持。论文建立了机翼ANSYS力学仿真模型对近似模型进行了修正。为使机翼力学近似模型逼近仿真结果,并减少近似模型中的设计变量数量,通过大量仿真数据实验分析,构造相关变量间的关联近似关系,和添加修正系数等方法,最终建立了与仿真结果逼近的含有较少未知量的力学近似模型。基于力学近似模型和机翼结构设计要求,建立了以机翼结构强度最大为目标,以质量和刚度指标为约束条件的优化模型。针对优化模型特点,应用改进的粒子群算法和遗传算法分别对机翼结构进行了优化,分析了两种优化方法对模型求解的适应性,最终获得了基于近似模型的机翼优化设计结果。论文对优化后的机翼进行了动力学分析,相比优化前机翼结构,优化后结构动力学特性变化较小,即优化后的机翼对整机的动力学特性影响较小。
[Abstract]:Wing is an important part of aircraft. At present, wing structure design is generally based on historical design cases, according to the current design parameters are modified to meet the design requirements, rarely adjust and optimize the design. The structure is more lightweight and reliable under the condition of rigid strength. In this paper, the approximate modeling method of the structural strength and stiffness of a wing with a large aspect ratio wing is studied, and the wing optimization model is established based on the approximate model. An efficient optimization algorithm is designed to optimize the wing structure. The approximate analytical model of wing mechanics is established by combining the empirical formula of aircraft structure strength calculation and the relevant theory of material mechanics, including: the approximate model of wing maximum stress. The approximate model of the maximum deflection of the wing and the approximate model of the torsional angle of the wing rib are fully considered in the approximate model, such as the position of the wing beam, the number of wings, the number of wings, and the design variables of the segmented (internal and outer wing) wing, which are not involved in the original mechanical model. In order to make the wing mechanics approximate model approach to the simulation results and reduce the number of design variables in the approximate model, the paper establishes the wing ANSYS mechanical simulation model to modify the approximate model. Based on the experimental analysis of a large number of simulation data, this paper constructs the correlation approximate relation among the related variables, and adds the correction coefficient and so on. Finally, a mechanical approximate model with less unknown quantity is established, which approximates the simulation results. Based on the mechanical approximation model and the design requirements of the wing structure, the maximum strength of the wing structure is established. According to the characteristics of the optimization model, the improved particle swarm optimization algorithm and genetic algorithm are applied to optimize the wing structure, and the adaptability of the two optimization methods to solving the model is analyzed. Finally, the results of wing optimization design based on approximate model are obtained. Dynamic analysis of the optimized wing is carried out in this paper. Compared with the optimized wing structure, the dynamic characteristics of the optimized wing structure change less. That is, the optimized wing has little effect on the dynamic characteristics of the whole machine.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V224

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