再入飞行振动环境试验等效性探讨

目的提高再入体实验室模拟再入飞行振动环境的等效性,确保地面环境试验结果的可靠性。方法首先分析再入飞行过程中受脉动压力等因素影响诱发的振动环境载荷特征。其次,基于飞行实测数据,分析再入飞行振动响应的空间分布规律和频域能量分布特征。最后,将飞行试验实测数据与传统实验室振动模拟试验结果进行对比,从载荷传递规律、空间分布规律、频谱特征等方面对主要关注区域"天地"响应存在的差异进行探讨,研究实验室等效模拟再入飞行振动环境的因素。结果针对特定的再入体结构,设置有限等效响应目标点,通过对试验系统动态特性分析、夹具优化设计、试验控制方式、振动台激振模式等多方面综合研究,可以提升再入飞行振动环境模拟等效性。结论提出了以"天地一致性"为目标的工程可行措施和实验室振动试验等效原则,为再入飞行振动环境的实验室等效模拟提供了支撑。

The Equivalence of Re-entry Flight Ground Vibration Test

This paper is to improve the equivalence of simulated re-entry flight vibration environment in re-entry body laboratories to ensure the reliability of the ground environment tests results. Firstly, re-entry vibration environment load characteristic induced by the fluctuating pressure and other factors in flight is analyzed. Secondly, the spatial distribution discipline and energy distribution characteristics in frequency domain of re-entry flight vibration response is investigated on the basis of measured flight test data. Finally, the measured flight vibration data are compared and analyzed with the traditional laboratory vibration simulation test results. The main focus area differences between ground tests and its re-entry flight missions are discussed from load transfer law, spatial distribution discipline frequency spectrum characteristics, and so on. Also the factors of laboratory equivalent simulation re-entry flight vibration environment are studied. For a specific re-entry structure, a finite equivalent response target point is set so as to promote the equivalence of vibration environment simulation of re-entry flight by studying the dynamic characteristics of the test system, optimization design of fixtures, test control methods and excitation modes of vibration table. The feasible engineering measures that can guarantee the consistency of vibration response of re-entry body between ground tests and its re-entry flight mission is presented and the laboratory vibration equivalent principle is proposed, which can provide support for improving the equivalence of ground environment test for re-entry flight vibration.