航空学报 > 2020, Vol. 41 Issue (2): 223327-223327   doi: 10.7527/S1000-6893.2019.23327

高速热流下薄壁结构声振响应分析及寿命预估

沙云东, 艾思泽, 赵奉同, 姜卓群, 张家铭   

  1. 沈阳航空航天大学 辽宁省航空推进系统先进测试技术重点实验室, 沈阳 110136
  • 收稿日期:2019-08-02 修回日期:2019-09-09 出版日期:2020-02-15 发布日期:2019-10-10
  • 通讯作者: 赵奉同 E-mail:zhao_ft@buaa.edu.cn
  • 基金资助:
    航空科学基金(20151554002)

Vibro-acoustic response analysis and fatigue life prediction of thin-walled structures with high speed heat flux

SHA Yundong, AI Size, ZHAO Fengtong, JIANG Zhuoqun, ZHANG Jiaming   

  1. Liaoning Province Key Laboratory of Advanced Measurement and Test Technology of Aviation Propulsion Systems, Shenyang Aerospace University, Shenyang 110136, China
  • Received:2019-08-02 Revised:2019-09-09 Online:2020-02-15 Published:2019-10-10
  • Supported by:
    Aeronautical Science Foundation of China (20151554002)

摘要: 现代飞行器飞行过程中发动机薄壁结构受高速热流冲击面临着极为严酷的工作环境,使结构产生大挠度动力学响应以及疲劳损伤破坏现象。为获取难以实测的热流冲击下结构声振响应规律及疲劳破坏时间,采用耦合有限元/边界元的方法进行数值模拟分析与热声疲劳试验相结合的方法,根据载荷效果构建与试验件尺寸完全一致的数值仿真模型,对热声载荷下薄壁结构进行仿真计算。采用功率谱密度(PSD)法分析频率响应峰值随声载荷变化规律,并通过改进的雨流计数法对声振响应数据进行统计分析,得到疲劳寿命时间。并对比声振响应仿真计算结果与试验结果发现误差小于2%,验证了数值仿真的可靠性。在此基础上,对高速热流冲击作用下薄壁结构进行数值仿真分析,通过分析频率响应峰值随温度和流速的变化规律获取不同温度各流速下结构声振响应及疲劳寿命变化规律,并阐述造成这种变化的原因。本文完成的工作可对高速热流环境下薄壁结构响应分析和寿命预估提供参考依据。

关键词: 高速热流, 薄壁结构, 热声疲劳, 寿命预估, 改进的雨流计数法

Abstract: When the modern aircraft flies, the thin-walled structure of the engine will be exposed to an extremely high-temperature environment, leading to the dynamic response of large deflection and fatigue damage. In order to obtain the structural dynamic responses of the structure in the high speed heat flux and the time of fatigue damage, which are generally difficult to measure, this paper adopts the method of coupled FEM/BEM for numerically simulate analysis and thermo-acoustic fatigue test. A numerical simulation model that is exactly of the same size as the test piece is constructed according to the load effect, and the thin wall structure under the thermo-acoustic load is simulated and calculated. The Power Spectral Density (PSD) method is used to analyze the peak frequency response to acoustic load variation, and the improved rain-flow counting method is used to analyze statistically the vibro-acoustic response data. The fatigue life time of the structure is then obtained. A comparison of the simulation results of acoustic response with the experimental results shows that the error is less than 2%, which verifies the reliability of the numerical simulation. A numerical simulation analysis of the thin-walled structure under the impact of high speed heat flux is carried out. The variation rules of stress response and life of the structure with temperature and flow velocity are summarized, and the reasons for the variation are expounded. The work completed in this paper can provide an important basis for response analysis and life prediction of thin-walled structures in high speed heat flux environment.

Key words: high speed heat flux, thin-walled structure, thermoacoustic fatigue, fatigue life prediction, improved rain-flow counting method

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