含凹坑缺陷圆柱壳的数值极限分析

使用文［１］提出的三维结构塑性极限分析的一般计算方法，我们对含凹坑缺陷的圆柱壳进行了数值极限分析．对凹坑和筒体各种组合的几何参数，本文给出了筒壳极限压力的上限．计算结果与现有的理论、实验和数值解进行了比较．本文调查和评估了各种形状和尺寸的凹坑对筒壳极限承载能力的影响规律，研究了对应于不同凹坑尺寸的筒壳两种典型的破坏模式．根据以上数值结果，本文采用几何参数Ｇ来反映凹坑各参数对筒壳极限压力的综合影响，并给出了估计带凹坑筒体极限压力的拟合公式．本文结果对含凹坑缺陷压力容器的安全评估具有重要参考价值

NUMERICAL ANALYSIS OF THE LIMIT LOADS FOR CYLINDRICAL SHELLS WITH PART THROUGH SLOTS

A numerical limit analysis is performed for cylindrical shells with part through slots using a general computational method for limit analysis of 3 D structures. The upper bounds for the limit pressures are given for a comprehensive range of geometric parameters. Some of the calculated results are compared with the results of detailed 3 D elastoplastic finite element analysis and where possible, with existing theoretical, experimental or numerical solutions. The effects of various shapes and sizes of part through slots on the load carrying capacity of cylindrical shells are investigated and evaluated. Two kinds of typical failure modes corresponding to different dimensions of slots are studied. Based on the numerical results, a geometric parameter G which combines the slot dimensions and the cylinder geometry is presented. It reflects reasonably the overall effect of slot on the limit load of a cylinder. A fit formula for estimating the limit pressure of a cylindrical shell with part through slot is obtained.