姿轨控发动机结构的中频振动响应分析  

Analysis of Medium Frequency Vibration Response of Attitude and Orbit Control Engine Structure

作　　者：吴丹 薛杰 艾鹏飞 王珺 谢石林[2] WU Dan;XUE Jie;AI Pengfei;WANG Jun;XIE Shilin(National Key Laboratory of Science and Technology on Liquid Rocket Engine,Xi’an Aerospace Propulsion Institute Xi’an 710100,China;School of Aerospace Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安航天动力研究所液体火箭发动机技术重点实验室,西安710100 [2]西安交通大学航天航空学院,西安710049

出　　处：《西安交通大学学报》2023年第11期12-20,共9页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(11872290)。

摘　　要：为了提高姿轨控发动机结构环境试验的设计水平,迫切需要研究相应的环境试验响应分析方法。基于姿轨控发动机中频振动特征明显这一特点,综合考虑各组件的模态数及结构特征,为姿轨控发动机建立了适用于中频响应分析的混合有限元-统计能量分析(FE-SEA)模型。在地面试验中,由于使用振动台,输入功率无法直接采用现有理论进行计算,提出了一种基于连接界面随机振动加速度功率谱密度的振动台激励输入功率计算方法,用以实现发动机结构在振动台激振下的响应预示。基于混合有限元-统计能量分析的姿轨控发动机结构响应预示结果与振动台试验的响应测量结果比较,结果表明,混合有限元-统计能量分析方法在中频分析频段内能够准确预示结构响应,当随机子系统的模态数大于3时,对应中心频率下的结构中频响应预示误差均小于±3 dB,具有良好的环境试验响应预示精度。混合FE-SEA方法的预示结果准确性与随机子系统在分析频带内的模态数密切相关,当模态数较小时,预示结果与试验结果在较低频带的误差变得显著。该研究内容为姿轨控发动机结构的中频振动响应分析提供了有效参考。To improve the design of environmental tests for attitude and orbit control engine(AOCE)structures,it is crucial to explore methods that suit environmental test response analysis.Considering the distinct mid-frequency vibration characteristics of AOCE structures and the modal densities and structural features of various components,a hybrid finite element-statistical energy analysis(FE-SEA)model suitable for mid-frequency response analysis of AOCE structures was established.During the ground tests,the use of a shaker made it impossible to calculate the input power directly.To address this issue,this paper proposes a method for calculating the shaker excitation input power based on the power spectral density of random vibration at the interface.This method can predicate the response of AOCE structures to shaker excitation.The comparison between the response prediction results based on the hybrid FE-SEA model and the response measurement results from the shaker experiments demonstrates that the hybrid FE-SEA method accurately predicts the structural response within the mid-frequency analysis range.For random subsystems with modal numbers higher than three,the predicted errors of mid-frequency responses at corresponding center frequencies are all less than±3 dB,indicating a favorable precision in environmental test response prediction.The accuracy of the hybrid FE-SEA method’s prediction results is closely related to the modal numbers of random subsystems within the analysis frequency band.Notably,when modal numbers are relatively small,the predicted results show significant errors compared to the experimental results in the lower frequency band.This study provides a valuable reference for the design of mid-frequency vibration environmental tests for AOCE structures.

关 键 词：姿轨控发动机结构 中频振动 混合有限元-统计能量分析 振动台激励 响应预示 

分 类 号：V439[航空宇航科学与技术—航空宇航推进理论与工程]