基于积叠线设计的弯掠叶片静强度优化方法

Optimization Method for Static Strength of Swept-Curved Blade Based on Stacking Line Design

关键词:  弯掠叶片  积叠线  散乱点插值  遗传算法  结构优化 

Key words:  Swept-curved blade  Stacking line  Scattered data interpolation  Genetic algorithm  Configuration optimization

摘要:

将叶片积叠方式作为结构设计的自变量,实现弯掠叶片的参数化建模,为适应优化设计的迭代要求,发展了一种能够自动更新的叶片有限元结构化网格模化方法。基于Voronoi图的自然邻点插值法,编制了高稳定性的气动载荷插值程序,可高效地完成流场分析结果向结构静强度分析中气动载荷的自动转换。引入子模型的思想对叶根边界条件进行等效处理,采用遗传算法建立基于叶片积叠线设计的自动优化方法,用以解决弯掠叶片静强度问题。通过高负荷弯掠叶片的工程实例应用,验证了优化方法的可行性和有效性,相对于初始设计,积叠线设计可以有效地改善叶片应力分布,应力幅值下降8.9%,使其满足静强度设计要求。 

Abstract:

After defining the stacking line of the blade as the structural design parameters, a parametrical structure model was established for the swept-curved blade. Moreover, for adapting to the requirements of the iterative in optimization, an automatically updating FEM structural grid modeling method was developed for the blade. The neighbor interpolation based on Voronoi diagram was used to write the high stability aerodynamic load interpolation procedures which could accomplish the automatic and efficient conversion between the pressure field and the aerodynamic load in the strength analysis. The sub-model thought was introduced to the equivalent processing for boundary conditions on the blade root. A general procedure was established by the genetic algorithm for the strength automatic optimization based on stacking line design to solve the strength problems of the swept-curved blade. The feasibility and effectiveness of the optimization method has been proved by the engineering application on a high load swept-curved blade case. Relative to the initial design, stacking line design can effectively improve the stress distribution, and the stress amplitude decreases by 8.9%, which can meet the static strength design requirements. 