形状缺陷条件下半球形封头屈曲特性研究

Buckling of hemispherical head with geometric imperfections

本文主要研究带有三种不同形状缺陷的半球壳的屈曲特性。半球壳的厚径比为0.013。采用锥形压头对半球壳进行加载,使其产生3 mm深的凹坑缺陷,然后在半球壳外表面施加均布载荷使其失稳,研究不同形状缺陷条件下半球壳的屈曲载荷和破坏模式。此外,文中展示了不同形状缺陷条件下缺陷幅值对屈曲载荷的影响规律,并与试验结果进行对比分析。结果表明,采用凹坑缺陷的评估标准更适用于球形封头的设计,而集中力缺陷的评估标准则过于保守。

The buckling properties of a hemispherical shell with three different shape imperfections were in⁃vestigated in this paper.The thickness-to-radius ratio of the hemisphere was 0.013.The conical indenter was used to apply the load on the hemisphere,so that the dimple imperfection of 3 mm depth was created.On the basis,the dented hemisphere was pressurized into instability.The buckling loads and collapse modes of the hemisphere were investigated under different shape imperfections.In addition,the effects of imperfec⁃tions amplitude on buckling loads were presented under different shape imperfections and compared with ex⁃perimental results.The results showed that the evaluation criterion of dimple imperfection was very suitable for the design of hemispherical domes,while the evaluation criterion of concentrated-force imperfection was too conservative.