碟形封头压力容器在内压作用下的弹塑性屈曲及后屈曲行为研究

基于ABAQUS对受内压碟形封头压力容器的弹塑性屈曲及后屈曲行为进行分析.通过非对称网格剖分技术诱发结构的屈曲行为,采用Riks算法捕捉完整的屈曲及后屈曲路径,分析屈曲载荷和后屈曲形态.计算结果表明,在内压作用下碟形封头压力容器过渡区域出现波状的分叉屈曲形态,随着加载的继续,过渡段将逐渐生成肉眼可视的褶皱,进入后屈曲阶段.后屈曲路径可以分为第一阶段与第二阶段.对引入初始厚度缺陷的结果分析可知,初始缺陷厚度的布置将对后屈曲路径产生影响,并降低结构的分叉屈曲载荷.

Elasto-Plastic Buckling and Post-Buckling of Internal Pressurized Torispherical Pressure Vessel

Elasto-plastic buckling and post-buckling of internal pressurized torispherical shell is analyzed by ABAQUS.Asymmetric mesh technology is an effective way to break symmetry and to induce the bifurcation buckling for simulating the buckling behavior of torispherical shell under internal pressure by Riks method.The buckling load is captured from the load-deflection curve of a typical point within the buckled zone.The results show that：As the internal pressure increased above some critical value,a wave like band had appeared in the knuckle region.After formation of the wave like deformation the pressure can be further increased substantially,causing the formation of visible buckles in the knuckle region.The post-buckling behavior can be departed as two phases：the first phase and the second phase.Initial imperfections have been introduced to the model.The post-buckling behavior has been affected by the location of the imperfections,and the bifurcation load has decreased caused by the initial imperfections.