Post-Buckling Behaviour of a Multi-Stable Composite Stiffened Specimen under Low-Cycle Fatigue – A Preliminary Study

This study experimentally investigates the effect of low-cycle fatigue loading on the evolution of buckling modes in a specimen consisting of a composite skin and four metallic stringers. The specimen was designed to achieve multiple stable configurations under compression through a tailored lay-up configuration that enables bucking to initiate in the thinner region and subsequently expand to the thicker region. The results indicate that the designed specimen was able of switching among different buckling modes under low-cycle fatigue loading. However, the skin-stringer separation was observed during high-amplitude fatigue loading.