Thermal Effect On The Dynamic Characteristics Of Structures

In this paper, the vibration characteristic of missile wing is analyzed under aerodynamic heating, including the thermal stiffness, thermal vibration characteristic and thermal flutter analysis.Firstly, the finite element method is used to analyze the temperature field and thermal stress. Using model of heat conduction, transient temperature field can be calculated. The temperature effect is taken as 'thermal load' to calculate thermal stress by general elasticity mechanics method. Secondly, thermal stress is taken as'pre-stress'to get extra stiffness matrix. Material parameters, like modulus of elasticity, are also should be considered, as they change with temperature. Then, the new system thermal stiffness can be got to calculate the nature mode of the structure. Thirdly, heating experiments are done to analyze the nature mode. The result is compared with FEM model's result. Some methods are used to identify the vibration nature mode with the experiment data. Finally, the environmental temperature and the aerodynamic force in the aerodynamic heating process are calculated to get the flutter speed.by means of FEM and test, the conclusions as following: thermal stress and the mechanical property of the material variety can reduce the nature frequency; the latter effect is stronger than the former; the nature frequency is decreased by the two factors; the higher nature frequency decreases more than the lower; the flutter speed is also decreased under the heating environment.