Investigation of the effect of metallic fuselage dents on compressive failure loads

The effect of dents in metallic aircraft fuselage was examined on the compressive failure load using the finite element method. The study considered a single impact dent on two different fuselage panels at various locations and impact speeds. The material used for the finite element models was aluminum alloy 2024-T3, a typical material used for fuselages of old transport aircraft. The finite element model consisted of impact analysis followed by either linear eigenvalue analysis or postbuckling compression analysis. These analyses were performed on both stiffened and unstiffened aluminum panels. It was found that, depending on a dent status in an aluminum panel, the dent might increase or decrease the compressive failure load of the panel compared with that of the virgin panel without a dent. The compressive failure load of a panel after a low-velocity impact was generally lower than that of the virgin plate. As the impact velocity increased, the failure load of the dented panel increased, exceeding that of its virgin plate. In addition, the existence of a critical impact velocity was noticed, at which the failure load of the dented panel reached maximum and after which it started to decrease.