考虑鸟撞的航空发动机叶片动态拓扑优化设计

Topological optimization design of aero-engine blade considering bird strike

为了实现航空发动机冷端风扇叶片在考虑鸟撞情况下的轻量化设计,从结构拓扑优化计算的角度出发,对该问题展开深入的研究并提出具体的解决方案。针对叶片优化中存在的优化模型建立,结构动态工况优化,多条件约束并存处理,多工况联合优化等关键问题,进行了理论上的深入分析研究,阐述了结构多约束、多工况动态优化的理论基础,并结合相应的数值计算平台,提出了风扇叶片分步优化计算的方案,对航空发动机叶片进行拓扑优化计算。计算结果显示,最终的叶片轻量化结构满足所有鸟撞与离心载荷多工况的优化约束条件,拓扑结构中材料分布合理,在满足适航条例强度要求的同时质量减少达37.9%,具有一定的实际参考应用价值,同时所提出的动态优化计算方案,在工程结构的动态优化中具有广阔的应用前景。

In order to achieve the lightweight design in consideration of the phenomenon of bird strike,it is necessary to dig into this issue and put forward a concrete solution from the perspective of structural topological optimization.Deep theoretical analysis and study were conducted to deal with those key points such as the construction of topological optimization model,the structural topological optimization while considering a type of dynamic load,and multiple constraints and cases in the dynamic problem.The theoretical basis of how to apply topological optimization method into the lightweight design was then clarified,and a computing scheme called multi-step optimizing calculation was also proposed and applied based on a corresponding numerical simulation platform.The lightweight design was based on those above key points and methods.The final optimized structure of aero-engine blade achieved its lightweight while satisfying all the optimization constraints under the different bird strike working conditions.The result showed that it could acquire about 37.9% mass reduction of the aero-engine blade.Thus,it is of great practical significance.Furthermore,the proposed topological optimization method for dynamic cases offers broad application pros-pect in most lightweight designs of engineering structures.