加筋真空容器稳定性分析

研究塑料加筋容器在真空状态下的稳定性·基于线性和非线性分支屈曲模型,用有限元法分析了这种组合壳体的临界载荷·分别计算了圆柱壳和椭圆封头的屈曲,并将总体屈曲载荷作为结构承载能力的理论值·利用平衡路径上两点间的割线,求解非线性路径的分支点·为了检查壳体稳定性的缺陷敏感度以及理论结果与真实的承载能力间的差别,做了两种壁厚容器的真空试验·理论与实验比较表明加筋真空容器稳定性对几何缺陷敏感·根据实验结果,建议了一个对于临界载荷理论值的修正系数·

Stability Analysis of Stiffened Vacuum Containers

The stability of stiffened vacuum plastics containers was studied. Based on the linear and non linear bifurcation buckling models, the critical loads of the combined shells were analyzed by finite element method. The buckling of shell and ellipsoid caps were computed. The overall buckling loads are considered as the theoretical values of the loading capacity. Using the secant of equilibrium paths between two points the bifurcation point of non linear paths was determined. To check the imperfect sensitivity of shell stability and the differences between the theoretical loading capacity and the tested loading capacity, the vacuum experiments of the containers with different thickness were carried out. Comparison between the theoretical results and the experiments shows that the stability of stiffened vacuum plastics containers is imperfect sensitive. Based on the experimental results,a correct factor for the critical loads was proposed.