点式连接航天器等效刚度模态分析方法  

Modal Analysis of Spacecraft with Dotted Joints Based on Equivalent Stiffness

作　　者：石川千 周徐斌[1] 张永涛[1,2] 杜冬[1] 李昊[1] 

机构地区：[1]上海卫星工程研究所,上海200240 [2]上海利正卫星应用技术有限公司,上海200240

出　　处：《航天器工程》2016年第1期31-39,共9页Spacecraft Engineering

基　　金：国家重大航天工程

摘　　要：针对点式连接航天器受接触影响而产生的非线性特性,提出了利用线性等效刚度代替非线性刚度以计算点式连接航天器模态的分析方法。首先采用有限元软件对点式连接航天器的非线性刚度进行分析,并基于非线性振动和结构动力学的原理,建立了等效刚度的计算方法。将等效刚度代入广义弹簧单元,最终获得点式连接航天器的简化模型并分析其模态。模态分析结果与试验结果对比显示,相比于传统分析方法,基于等效刚度的简化模型精确地预测了点式连接航天器的模态,有利于提高点式连接航天器的动力学仿真分析精度。To include the interaction effect in modal analysis, a novel model analysis method em- ploying the equivalent stiffness of dotted joints is proposed in this paper. Firstly,a full-size finite element model of a dotted joint for a spacecraft structure is established. The nonlinear connection stiffness of dotted joint corresponding to different bolt quantities and loads are predicted. A novel method based on nonlinear dynamic theory is proposed to calculate the equivalent stiffness of dot- ted joints. Then,a simplified FE model of the spacecraft structure is established by employing the generalized spring element and the calculated equivalent stiffness. The modes of the spacecraft structure are predicted by the simplified FE model and are also measured in experiments. The predicted modes coincide quite well with the experimental results. The proposed modal analysis method is proven to be accurate and will facilitate the dynamic analysis of spacecraft structure with dotted joints.

关 键 词：航天器 点式连接 模态 等效刚度 非线性特性 

分 类 号：V414[航空宇航科学与技术—航空宇航推进理论与工程]