Tao Weiming

(Institute of Solid Mechanics, Zhejang University, Hangzhou 310027)

Yang Yajun

(Department of Electromechanical Engineering,Zhejiang University of Science and Technology,Hangzhou 310012)

Guo Yimu

(Institute of Solid Mechanics, Zhejang University, Hangzhou 310027)

Abstract: The localized plastic buckling occurred in the transition region in the torispherical end closure of a pressure vessel is analyzed by FEM. By introducing the initial geometrical imperfection, which is determined from the elasto-static displacements, into the zone where it is circumferentially compressed, the arc-length method RIKS procedure is employed to simulate the deformation process during loading. The buckling point is captured from the load-deflection curve of a typical point within the buckled zone, and the corresponding buckling load is calculated. The results show that the buckling load is quite sensitive to the artificial geometrical imperfections. Furthermore, after the first buckling initiated, the succeeding loading will lead to more wrinkles within the compressive transition region. Additionally, the case that with four distributed imperfections is also analyzed. It can be seen that the interaction between the imperfections is very weak before or even after the first buckling occurred, which means the buckling is fairly localized.

Key words: Pressure vessel  Elasto-plastic buckling  Internal pressure  Finite element method

CLC No: TU311.2  TQ051.3

Received 20030609, received in revised form 20040308