热声载荷环境高速飞行器加筋壁板非线性振动响应特性研究
Nonlinear Vibration Response Characteristics of Stiffened Panel Structure of High Speed Aircraft under Thermoacoustic Load
周晓天 1沙云东 1杨延泽1
作者信息
- 1. 沈阳航空航天大学 航空发动机学院,沈阳 110136
- 折叠
摘要
目的 针对热声载荷环境下高速飞行器排气道加筋壁板结构的大挠度非线性振动响应特性问题展开研究.方法 基于薄壁结构大挠度运动控制方程,开展了加筋壁板结构在热声载荷下的非线性响应仿真计算,给出了加筋壁板结构运动方程,分析了发生热屈曲的临界温度,并运用有限元方法进行数值模拟,计算了加筋壁板结构在不同载荷下的非线性振动响应特性.结果 模态频率的一致性在结果中得到体现.计算了多参数即结构、温度、声压级变化下壁板结构的响应变化.加筋会使壁板结构基频升高,响应降低;屈曲前随温度上升,结构基频不断降低,最低时处于临界温度附近;屈曲后随温度上升,结构基频不断升高.基频幅值在温度上升的过程中先升高后降低.声压级每升高 6 dB,等效应力平均升高 1.98倍,验证了响应的非线性特性.结论 结构、温度、声压级参数对加筋薄壁结构非线性振动响应有较大影响,加筋壁板结构在温度上升过程中由屈曲前稳定状态变为屈曲失稳状态,又逐步变为屈曲后稳定状态.本文所做的工作可为其他薄壁结构,尤其是加筋壁板结构的非线性振动响应特性计算与分析提供参考依据.
Abstract
The work aims to study the large deflection nonlinear vibration response of stiffened panel structure of high speed aircraft exhaust duct under thermoacoustic load.Based on the large deflection motion governing equation of thin-wall structures,the nonlinear response simulation of a stiffened panel structure under thermoacoustic load was carried out.The motion equation of the stiffened panel structure was given,the critical temperature of thermal buckling was analyzed,and the nonlinear vibration response characteristics of the stiffened panel structure under different loads were calculated by numerical simulation according to the finite element method.The consistency of the modal frequency was reflected in the results.The response changes of the panel structure with multiple parameters such as structure,temperature and sound pressure level were calculated.The rein-forcement increased the fundamental frequency and decreased the response of the panel structure.Before buckling,the funda-mental frequency of the structure decreased with the increase of temperature,and the lowest frequency was near the critical temperature.The fundamental frequency of the structure increased with the increase of temperature after buckling.The funda-mental frequency amplitude increased first and then decreased during the temperature rise.For every 6 dB increase of sound pressure level,the equivalent stress increased by an average of 1.98 times,which verified the nonlinear characteristics of re-sponse.The parameters of structure,temperature and sound pressure level have great influence on the nonlinear vibration re-sponse of the stiffened thin-walled structure.The stiffened thin-wall structure changes from the pre-buckling stable state to the in-buckling unstable state and then to the post-buckling stable state gradually during the temperature rise.The work in this paper can provide reference for the calculation and analysis of nonlinear vibration response characteristics of other thin-walled struc-tures,especially stiffened panel structures.
关键词
高速飞行器/加筋壁板/热声载荷/非线性振动/热屈曲/薄壁结构Key words
high speed aircraft/stiffened panel/thermoacoustic load/nonlinear vibration/thermal buckling/thin-walled structure引用本文复制引用
基金项目
辽宁省"兴辽英才计划"(XLYC1802068)
出版年
2024
NETL
NSTL
万方数据