Elastic-plastic deformation of thin-walled structures based on a twopole finite element

Statement of the problem. The aim of the work is to apply the constitutive equations of the theory of plastic flow obtained by the authors without separating the strain increments into elastic and plastic parts to determine the stress-strain state of structures in which stress concentration zones exceeding the yield strength of the material are formed under loading. Results. The proposed version of the constitutive equations of the theory of plastic flow without separating the strain increments into elastic and plastic parts is used to obtain the stiffness matrix of a mixed prismatic finite element with nodal unknowns in the form of displacement increments and stress increments at the loading step. The sought values of the internal point of a finite element with triangular bases were approximated using linear functions. Conclusions. A specific example shows the practical coincidence in the results of calculations using the constitutive equations of the theory of flow and the proposed version of the theory of plasticity.