矢跨比对加劲球壳弹性屈曲性能的影响

Influence of Rise-span Ratio on the Elastic Buckling Behavior of Stiffened Spherical Shell

加劲球壳的承载力取决于整体稳定性。由于加劲球壳属于各向异性壳,影响其屈曲性能的因素较多,至今没有统一的方法获取其整体失稳时的临界荷载。矢跨比是球壳结构屈曲性能分析中的关键因素之一,文中针对矢跨比对加劲球壳弹性屈曲性能的影响进行分析。先利用ABAQUS软件对球面薄壳进行屈曲分析,验证有限元分析的可靠性;再建立跨度恒定矢高变化的加劲球壳的有限元缩尺模型,分析弹性屈曲临界荷载与矢跨比之间的关系。研究结果表明,当环向与经向加劲肋间距比值在2.55-3.65范围内,屈曲临界荷载与矢跨比呈正相关关系。有效地增大矢跨比有利于提高其整体稳定性。

The bearing capacity of stiffened spherical shells depends on its overall stability. Because the shell is anisotropic, there are many factors affecting its buckling behavior. So far, there is no unified approach to obtain the overall instability critical load. Since rise-span ratio is one of the key factors of buckling behavior analysis for spherical shell structure, the influence of rise-span ratio on elastic bucking behavior of stiffened spherical shell is analyzed. At first, using ABAQUS software, the buckling analysis of thin spherical shell is taken to verify the reliability of finite element analysis. Then, scale stiffened shell models with constant span and various rise are established to analyze the relationship between the elastic buckling critical load and rise-span ratio. The results show that the change of critical buckling load is positively correlated with the rise-span ratio, where the ratios of ring spacing and stringer spacing are in the range of 2.55-3.65. Therefore, increasing the rise-span ratio can effectively enhance its overall stability.