ON THE INCREASE OF COMPUTATIONAL ALGORITHM EFFICIENCY FOR ELASTOPLASTIC SHELL ANALYSIS

Presents a robust and unconditionally stable return-mapping algorithm based on the discrete counterpart of the principle of maximum plastic dissipation. Develops the explicit expression for the consistent elast oplastic tangent modulus. All expressions are derived via tensor formu lation showing the advantage over the classical matrix notation. The i ntegration algorithm is implemented in the formulation of the four-nod e isoparametric assumed-strain finite-rotation shell element employing the Mindlin-Reissner-type shell model. By applying the layered model, plastic zones can be displayed through the shell thickness. Material non-linearity described by the von Mises yield criterion and isotropic hardening is combined with a geometrically non-linear response assumi ng finite rotations. Numerical examples illustrate the efficiency of t he present formulation in conjunction with the standard Newton iterati on approach, in which no line search procedures are required. Demonstr ates the excellent performance of the algorithm for large time respect ive load steps.