基于梁模型的无轴承尾桨等效建模及模态分析  

Equivalent Modelling and Modal Analysis of Bearingless Tail Rotor based on Beam Model

作　　者：张英琦 周如传 黄国科 李晓彬[1] ZHANG Yingqi;ZHOU Ruchuan;HUANG Guoke;LI Xiaobin(China Helicopter Research and Development Institute,Jingdezhen 333001,China)

机构地区：[1]中国直升机设计研究所,江西景德镇333001

出　　处：《直升机技术》2024年第3期11-17,共7页Helicopter Technique

摘　　要：无轴承尾桨叶开展模态试验时,出现同一阶对称型与反对称型摆振频率差异较大的现象。为了揭示频率出现差异的原因,对该无轴承尾桨叶进行有限元分析与试验研究。建立无轴承尾桨有限元模型时,考虑到无轴承尾桨多路传力方式及根部边界约束复杂的特点,采用分步式建模方法:第一步基于静力缩聚方法对柔性梁根部夹持区等效梁进行计算,获得根部剖面等效刚度;第二步基于三维等效梁模型计算方法,采用ABAQUS软件建立无轴承尾桨的有限元梁模型。对不同根部边界约束下的无轴承尾桨动特性进行了分析研究,并开展了不同根部边界条件下的静态动特性试验,计算结果与试验结果吻合良好。研究结果表明:柔性梁根部边界条件对桨叶摆振模态频率影响较大,是桨叶出现同一阶对称型与反对称型摆振频率较大差异的原因;分步式建模方法可以兼顾无轴承尾桨动特性计算的精确性和计算效率,满足工程设计需求。During the modal test of the bearingless tail rotor,there is a great difference between the same order symmetric and antisymmetric shimmy frequency.In order to reveal the reason of the frequency difference,the finite element analysis and experimental study of the bearingless tail rotor were carried out.When establishing the finite element model of the bearingless tail rotor,considering the characteristics of the multi-channel force transmission and the complex root boundary constraints of the bearingless tail rotor,the step-by-step modeling method was adopted.In the first step,the equivalent beam in the clamping zone of the flexible beam root was calculated based on the static condensation method,and the equivalent stiffness of the root section was obtained.The second step was based on the three-dimensional equivalent beam model calculation method,the finite element beam model of the bearingless tail rotor was established by using ABAQUS software.The dynamic characteristics of the bearingless tail rotor under different root boundary constraints were analyzed and studied,and the static dynamic characteristic tests under different root boundary conditions were carried out.The calculated results were in good agreement with the experimental results.The results showed that the root boundary condition of the flexible beam had a great influence on the blade shimmy mode frequency,which was the reason for the great difference between the blade shimmy frequency of the same order symmetric type and anti-symmetric type.The step-by-step modeling method could take into account the accuracy and efficiency of the calculation of dynamic characteristics of bearingless tail rotor,and met the requirements of engineering design.

关 键 词：直升机 无轴承尾桨 有限元建模 模态分析 

分 类 号：V214.33[航空宇航科学与技术—航空宇航推进理论与工程]