航天器与运载火箭耦合分析相关技术研究进展

本文以载荷分析为主要内容, 概述航天飞行器结构动力学研究的一些进展. 首先介绍航箭(航天器/运载火箭简称为航箭) 耦合系统载荷分析基本思想. 然后介绍以下3 个方面的载荷分析方法: (1) 采用基础激励理论初始载荷分析的近似方法; (2) 考虑航箭耦合影响的航天器/运载耦合系统分支模态综合法. 导出采用约束模态质量界面加速度的航天器载荷计算方法; 当仅考虑静定约束特殊情况时, 退化的方程与Chen 采用有限元法导出的方程相同. 给出新航天器载荷瞬态分析技术, 即一个以前的航天器/运载耦合系统载荷结果可以用来获得相同运载火箭发射一个新航天器结构的必要的载荷信息. (3) 考虑航箭耦合影响的航天器/运载耦合系统模态综合法. 包括: 固定界面模态综合法, 以及航天器/运载耦合的界面综合动态响应计算新方法. 最后, 介绍验证载荷分析技术. 简要讨论验证技术的重要性, 提出了采用试验与理论相结合的结构动态试验仿真技术,该方法包括了一套修正数学模型的新技术, 称之为子结构试验建模综合技术. 该方法已应用于复杂的结构建模. 在进行CZ-2E 运载火箭实尺模态试验之前, 用建议的模态试验仿真技术给出CZ-2E 模态参数的预示结果, 并与随后获得的实际模态试验结果相比, 两个结果彼此之间高度一致. 这个结果证明了模态试验仿真技术已成功地预示了CZ-2E 运载火箭的模态参数, 验证了建议的模态试验仿真技术的可靠性. 讨论了振动台振动试验仿真技术. 介绍了振动台振动试验仿真的几个关键技术. 包括: 有限元模型修正技术, 40 t 振动台系统台面控制仿真方法和D 卫星振动台振动试验仿真.

PROGRESSES IN RESEARCH ON COUPLED ANALYSIS TECHNOLOGY FOR SPACE VEHICLE AND LAUNCH VEHICLES

With focus laid on loads analysis, some progresses of structural dynamics in the field of space vehicle design are summarized. The paper first presented some fundamental ideas of load analysis which has been applied in space vehicle / launch vehicle coupling systems. And then load analysis methods were explored in the following three directions: 1) Approximate initial load analysis methods by means of basis excitation theory in which coupling effects of the space vehicle / launch vehicles are neglected; 2) A branch modes synthesis method for the coupled space vehicle / launch vehicle system with the coupling effects taken into account. Based on the interface acceleration of constraint modes mass, the load estimation of the space vehicle / launch vehicle coupled system was derived analytically. Furthermore, if only static constraints modes mass is considered, the reduced equation (as a special case of this method) is actually identical to the equation derived by Chen using FEM. Furthermore, a new technique for space vehicle load transient analysis was also established. With the technique, previous analyzing results of space vehicle / launch vehicle coupling systems can be extended to new coupling systems between the same launch vehicle and a new space vehicles; 3) A modal synthesis method for the space launch / launch vehicle coupled systems. Several modal synthesis methods were studied, the fixed-interface modal synthesis method was first presented ,and the method was applied to Ariane-5 launch vehicle dynamic response analysis, a new method for deriving dynamic response of the space launch / launch vehicle system was then given based on coupling interface synthesis; Finally, verification techniques of the load analysis methods were elucidated. After a brief discussion of the importance of the verification techniques, a new technology of structure dynamic test simulation is proposed to combine the experimental results with the theoretical analyzing results. This is a set of new techniques for updating mathematics model, which is named as synthesis techniques based on the substructure experimental modeling. The approach has been applied to the modeling of such complex structures as a large strap-on launch vehicle Long March 2E (LM-2E) and a 40 T shaker system. The proposed techniques were demonstrated with LM-2E as follows: the predicted modes were derived before the modal test of real full scale LM-2E launch vehicle; and the modes were then compared with actual test results obtained thereafter. The two results turned out to be highly consistent between each other. The experiment proves that the modal parameters of the LM-2E had been successfully reproduced by the proposed modal test simulation techniques ,and the reliability of the proposed techniques is thus verified. The vibration test simulation techniques of a 40 T shaker were also discussed. Key simulation techniques for the vibration test are summarized, including the modification technique for the shaker FEA mathematics model; the simulation technique of the table-board control for vibrating tests of a 40 T shaker system and the simulation technique of D satellite shaker vibration tests.