环形曲面结构开孔形状动力学优化设计

发布时间：2018-05-28 21:15

本文选题：环形曲面 + 序列响应面　；参考：《南昌航空大学》2015年硕士论文

【摘要】：本文简述了环形曲面开孔结构的发展与应用,并阐述了国内外结构优化研究现状。针对有限元法求解复杂问题响应优化过程耗时长的问题,提出了基于继承性均匀设计序列响应面的优化方法;在此基础上,开展了以改善结构动力学性能为目标的环形曲面结构开孔形状优化。主要工作及结论如下:提出一种基于继承性均匀试验样本点设计策略和子区域自适应缩放移动准则的序列二次响应面建模方法,达到提高优化效率的目的。通过典型测试算例和工程优化案例的优化设计验证了该方法的有效性。为计算耗时的工程优化设计问题提供了一种有效的方法。针对回转壳开孔形状优化问题,运用参数映射定义了基于超椭圆方程描述的回转壳面开孔封闭曲线的参数化表达,通过准弧长插值点生成方法实现了空间开孔边界的高精度曲线拟合,保证了回转壳曲面开孔结构的快速建模。优化结果表明使用扭曲超椭圆函数描述环形曲面薄壳结构开孔形状能有效扩大一、二阶频率带隙,降低开孔边界应力,提高屈曲载荷。复合材料的横向剪切刚度比纵向拉伸刚度小得多,而横向剪切效应对于振动频率、弯曲变形和弹性失稳载荷影响很大。因此,以一、二阶频率带隙最大化为目标对复合材料圆锥薄壳结构开孔形状进行优化。选取0°与90°、45°与-45°两组正交角度作为铺层角度参数,在不同的铺层角度组合下进行圆椎壳开孔形状优化。结果表明在相同铺层条件下,超椭圆开孔的优化结果优于圆形开孔。但是,不同开孔形状最大频率带隙对应的纤维铺层角度不同,所以对纤维铺层参数与开孔形状参数进行同步优化能够进一步提高频率带隙。
[Abstract]:In this paper, the development and application of annular surface perforated structure are briefly described, and the research status of structure optimization at home and abroad is described. In order to solve the problem of complex problem response optimization with finite element method, an optimization method based on inherited uniform design sequence response surface is proposed. The opening shape optimization of annular curved surface structure is carried out to improve the dynamic performance of the structure. The main work and conclusions are as follows: a sequential quadratic response surface modeling method based on inherited uniform test sample point design strategy and sub-region adaptive scaling moving criterion is proposed to improve the optimization efficiency. The effectiveness of the method is verified by the optimization design of typical test cases and engineering optimization cases. It provides an effective method for calculating the time-consuming engineering optimization design problem. Aiming at the optimization of open hole shape of rotary shell, the parametric expression of open hole closed curve of rotary shell surface based on hyperelliptic equation is defined by parameter mapping. The high precision curve fitting of the space opening boundary is realized by the method of quasi-arc length interpolation, which ensures the fast modeling of the open hole structure of the curved surface of the rotary shell. The optimization results show that the torsional hyperelliptic function can effectively enlarge the first and second order frequency band gap, reduce the boundary stress and increase the buckling load. The transverse shear stiffness of the composite is much smaller than that of the longitudinal tensile stiffness, and the transverse shear effect has a great influence on the vibration frequency, bending deformation and elastic instability load. Therefore, the opening shape of composite conical thin shell structure is optimized with the aim of maximizing the frequency band gap of the first and second order frequency. Two groups of orthogonal angles, 0 掳and 90 掳, 45 掳and -45 掳, were selected as laying angle parameters. The results show that the optimization results of hyperelliptic holes are superior to those of circular holes under the same layering conditions. However, the fiber layering angle is different with the maximum frequency band gap of different hole shapes, so the simultaneous optimization of the fiber laying parameters and the opening shape parameters can further improve the frequency band gap.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;TB122

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