Abstract: The elastic-plastic finite element analyses of the internal pressure vessels with the different ratios of the diameter of nozzle to the diameter of vessel are carried out to investigate the stress concentration in the nozzle-vessel junction. The results show that the heaviest stress concentration is found at the interval nozzle-vessel junction of the longitudinal symmetry plane, while the stress concentration around the external junction is decrease because of the welded joint. In the process of loading, the stress around the junction linearly increases at first and then the range of the high stress area enlarges. The ratio of the diameter of nozzle to the diameter of vessel has greater effect on the distribution area of high stress in plastic deformation stage. Compared with large opening without nozzles, the stress concentrations around the junction are sharply reduced because of the nozzles.

Key words: Internal pressure vessel   ,  Elastic-plastic analysis ,  , Large nozzle

摘要： 针对筒体带大接管的内压容器在相贯区附近会产生较高的应力集中这一问题,考虑材料的塑性变形
特性,对不同开孔率的内压容器结构进行了一系列的弹塑性有限元分析。计算结果表明,纵向对称面筒体与接管的
内相贯处是应力集中最严重的部位,外相贯处由于有焊接接头而使应力集中大大缓解。在逐步加载过程中,加载前
期相贯区周边应力呈线性增长,一定程度后主要表现为高应力范围的扩大。对于均处于塑性阶段的结构而言,开孔
率的大小对高应力区的分布范围影响较大。与未带接管的大开孔结构相比,接管的添加大大降低了孔周边的应力
集中。

关键词: 内压容器 , 弹塑性分析 , 大接管