大型复杂航天器结构有限元模型的验证策略研究

Finite Element Model Verification Strategy of Large Complex Spacecraft

大型复杂航天器结构有限元模型的合理性和准确性在航天器研制过程中具有重要意义,它是开展星箭耦合分析以及力学环境条件设计等工作的基础。首先综合有限元建模、模态试验、相关分析和模型修正等技术构造了一套系统的航天器结构有限元模型试验验证策略;然后,针对我国新一代大型卫星平台——东方红四号卫星开展了整星有限元模型的试验验证研究,其中整星模态试验以及模型修正等研究工作属首次在东方红四号卫星平台上成功实施。修正后有限元模型对整星主模态频率预测误差小于5%,模态置信准则大于0.6,预示精度达到工程要求。

Precise finite element model plays a key role in the design of large complex spacecraft such as satellite. It provides the research platform for coupled load analysis and mechanical environment predication. A systematic model verification strategy consisted of finite element modeling, modal test, correlation analysis and model updating is proposed in this paper. The strategy is then applied in the model verification of DFH - 4. Among all the presented researches, modal test and model updating are suppos- edly to be first time successfully implemented on the DFH - 4. After updating, the verified finite element model is able to accurately reproduce measured modal data. Frequency deviations between experiment and updated model are less than 5 % . The modal assurance criteria of the concerned modes also increase obviously.