INVESTIGATIONS OF STRAIN AND STRESS STATE AND CAPACITY IN SHORT CYLINDRICAL SHELLS UNDER INTERNAL PRESSURE

Abstract

In the paper it has been assumed that a triaxial stress and strain state occurs in a shell. The finite element method was used and owing to that digitization of the problem was possible. Such digitization was necessary for a numerical analysis of the moment stress state in the shell. On the ground of physical relations of the Prandtl-Reuss plastic flow theory an algorithm was formulated. The algorithm was a basis of calculating strains and stresses and determining capacity in a short cylindrical shell with rigid bottoms. The shell was subject to internal pressure. Experiments were carried out, as well. The results obtained with: equations of the membraneous shell theory, using plastic flow theory, relations of the finite element method, taking the moment state in the shell into consideration were compared with the results of experiments. From the obtained strain curve for a given material the necessary parameters for calculations were determined. It has been shown that the experimental results approximately confirm the results obtained with the finite element method. The results obtained with the membraneous theory of shells are considerably different, mainly in the area adjoining on the rigid flanges.