Cumulative buckling deformation of stiffened panel under cyclic loading

In this study, the cumulative buckling deformation process is evaluated for a stiffened panel subjected to two different uniaxial cyclic loading conditions, namely compressive loading only and alternating tensile-compressive loading. The impact of the cyclic load on the ultimate strength of the panel is then estimated. It should be noted that the occurrence of permanent deformations could be simulated by finite element analysis using a suitable model capable of correctly capturing the deformation components. The results show that the structure accumulates a deformation that appears to grow almost linearly therefore, consequently, it is realistic to expect that if a large number of load cycles of this magnitude are imposed, the accumulated plastic deformation can be quite severe. Furthermore, it is found that these residual deformations, caused by an entity of the cyclic load lower than the design limit, affect the tensile strength of the stiffened panel. Finally, the effects on the numerical evaluation of the ultimate strength of the structure are shown.