关键词: 高超声速, 热颤振, 热模态试验, 热模态分析, 地面共振试验(GVT)

Abstract:

Temperature elevator can affect the natural frequencies and normal modes of hypersonic vehicles in aerodynamic heating, and thus the flutter characteristics of the vehicles can change with the dynamic properties. Focusing on the special characteristics or hypersonic vehicles, this paper analyzes the research of a thermo-modal test method for a wing structure. A thermo-modal test method is presented, and a thermo-modal test system using this method is established. For the purpose of certification, a titanium wing model is designed and manufactured, and its thermo-modes with variation of boundary condition are acquired. The nomal modes under several thermal circumstances are investigated during the test, including heating evenly at single side and both sides, heating unevenly at both sides, and heating to time variation. The results show that elevated temperature has a significant effect on the natural frequencies of the wing model, and the test method has high engineering practical value. To simulate these phenomena, theoretical analysis of thermo-modes of the wing is performed by a finite element model using the software NASTRAN. The results agree well with the test results, showing that this analysis method can meet the requirement in engineering.

Key words: hypersonic, thermo-flutter, thermo-modal test, thermo-modal analysis, ground vibration test (GVT)