Evaluation of residual plastic strain on a stiffened panel subjected to compression and tension-compression cyclic load

In this study, the process of accumulation of residual plastic deformation is numerically investigated for a stiffened panel under compression and traction-compression cyclic loading conditions. In particular, the difference between results obtained from the only compression cyclic loading case and the tractioncompression loading is shown, highlighting the influence of the changing in the load sign. This is investigated also taking into account different hardening models of the material, namely isotropic or kinematic. The numerical model describes a stiffened panel including the transversal frames, cyclically subjected to axial loading under different time histories: in particular, the maximum compressive load is applied as a fraction of the ultimate load of the intact structure. Finally, the effect of the accumulated plastic deformations on the ultimate strength of the structure is analyzed, in order to evaluate the influence of the cyclic load history.