弹(箭)常用的外防热涂料在贮存过程中经常出现裂纹、开裂、脱落等现象。为了研究在不同温度下,外防热涂层的应力应变变化情况,为强度分析提供参考依据,建立了某发动机壳体及涂层的三维有限元模型,研究了随温度变化涂层应力应变的变化特点。计算发现,常温向高温转化时,涂层的各向应力均为负值即压应力,此时应该用最大主应变准则来判断材料是否破坏;常温向低温转化时,各向应变都为负值即压应变,此时应该用Mises应力或者最大拉应力准则来判断结构的安全性。

The outside heat-preventing coating of missile (rocket) often cracks, peels off and so on. In order to research the change of stress and strain of outside heat-preventing coating with different temperature, providing a reference for strength analysis, a 3D finite element model was established to study the change characteristics of stress and strain with different temperature. The result shows that the strain of coating will be negative value when the temperature increases, the maximum principal strain criterion should be used to judge whether the material is damaged. The strain of coating will be negative value when the temperature decreases, the Mises stress or maximum principal stress criterion should be used to judge whether the material is damaged.