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为了推动功能梯度材料(FGM)在高超音速飞行器热防护结构设计中的应用,旨在探讨不同温度场对热防护壳模态频率的影响,提供热防护壳动力学设计参考。从陶瓷金属基FGM的热物性参数模型入手,结合圆柱薄壳能量原理,建立FGM圆柱壳的模态方程。在此基础上,首先分析热物性参数变化规律对FGM壳模态频率的影响,然后探讨考虑热应力后不同热环境下FGM壳模态频率的变化规律。结果表明,FGM物性参数变化对模态频率的影响没有热力耦合影响明显;温度梯度<300 K时,物性参数变化对模态频率起主导作用,反之温度梯度>300 K时,热应力和热变形对模态频率起主导作用。
In order to promote the application of FGM in the design of thermal protection structure of hypersonic vehicle, this paper aims to explore the influence of different temperature field on the modal frequency of thermal shield shell, and provide reference for thermal shield design. Starting from the thermophysical parameter model of FGM, the modal equations of FGM cylindrical shell are established based on the energy principle of cylindrical shell. Based on this, the influence of the variation of thermal parameters on the modal frequency of the FGM shell is first analyzed, and then the variation of the modal frequency of the FGM shell under different thermal environments is discussed. The results show that the change of physical parameters of FGM has no obvious influence on the modal frequency without thermal coupling. When the temperature gradient is less than 300 K, the change of physical parameters plays a dominant role on the modal frequency. On the contrary, when the temperature gradient is> 300 K, the thermal stress and thermal deformation Moderate frequency plays a leading role.