基于自动有限元建模的民机机翼结构布局优化

Layout optimization of civil airplane wing structure based on automated finite element modeling

针对民用飞机中广泛采用的双梁式机翼结构,以机翼结构纵向构件(长桁)和横向构件(翼肋)的数量为参数生成机翼CAD模型,然后基于Patran的PCL(Patran Com-mand Language)语言,根据整体模型分割、局部模型编号、局部网格控制、整体有限元生成的思路,实现了以纵向和横向构件的数量变化为基础自动进行机翼结构有限元模型的构建及分析,并将上述流程集成到机翼结构的布局优化中.最后参照某大型民用飞机的机翼外形尺寸建立了CAD模型,以机翼的静强度、刚度和蒙皮稳定性为约束,以机翼结构质量最低为目标,对上、下蒙皮长桁和翼肋数量进行了优化.优化后的布局使机翼结构质量降低了10.1%,表明了布局优化方法的有效性和可行性.

Focusing on the widely-applied two spar wing structure on civil airplanes, a wing CAD model was created parametrically according to the numbers of its stringers and ribs. Then a wing structure finite ele- ment method（FEM） model was constructed automatically by Patran command language （PCL）, it was realized by 4 major steps, which were geometry model segmentation, geometry segment renumbering, segment mesh definition and FEM model generation. A complete procedure was fulfilled to construct and analyze a wing structure FEM model automatically after the numbers of its stringers and ribs had been changed, then it was integrated into a wing structure layout optimization that could be applied in preliminary design. In the end, a case study model was constructed referring to a typical civil airplane wing. Under the constraints of static strength, stiffness and skin stability, the numbers of stringers and ribs were optimized to achieve a minimum structure weight. Results show that the optimal layout brought a 10.1% structure weight reduction, which in- dicates the effectiveness and feasibility of the optimization.