直升机结构动特性建模技术研究

Investigation of Modeling Techniques for Helicopter Structure Dynamic Behaviour

在直升机设计阶段通过建模分析进行全机动特性设计 ,准确地预测全机振动响应是控制和降低直升机振动水平的关键技术 ,本文以某直升机为研究对象 ,对机体结构的动特性建模技术进行了深入的研究。采用从部件到全机建模的研究策略 ,把整个机体分成尾段、舱门、机身段 ,分别进行有限元建模、动特性试验、相关分析、模型修改技术和建模准则的研究。在此基础上 ,对部件连接界面建模分析 ,组装修改后的各部件模型 ,建立全机动特性分析模型。通过对该机动力学建模、试验相关分析与模型修改 ,大大增强了分析模型的预测能力 ,达到了 4 0Hz以内的频率误差小于 1 1 %的预测精度 ,突破了对直升机复杂结构建模关键技术 ,建立了适用于直升机结构动力学分析的建模准则 ,在该机动特性设计中取得了成功。

The key techniques of helicopter vibration control and reduction involves the design of dynamic behavior and accurate prediction for dynamic response through modeling analysis during the phase of helicopter design. In this paper, a comprehensive investigation has been carried out taking a helicopter as research target. The modeling strategies, which divide whole fuselage into tail pylon, main fuselage and doors, and perform the study of finite modeling, dynamic test, test analysis correlation, model improvement techniques and modeling criterion respectively, is employed. On based of that, the improved component models are installed together into whole fuselage dynamic model by modeling the intersections among the components. Through the dynamic modeling, test analysis correlation and model improvement, the ability of dynamic behavior prediction of the analysis model is greatly increased. The frequency prediction error is below 11% compared to test results of the fuselage natural frequencies lower than 40 Hz The key techniques for the complicated helicopter structure modeling has been made a breakthrough and the modeling criterion suitable for helicopter structure dynamic analysis has been concluded, which were used in dynamic design of the helicopter successfully.