Influence of Loading Conditions on the Impact Damage Resistance of Composite Panels

In this paper the onset of impact induced delaminations in stiffened composite panels is analysed by using an approach based on a threshold critical impact force. This approach is adopted in combination with geometrically non-linear finite element analyses in order to investigate the influence of the in-service loading conditions on the impact damage resistance of the composite panels. An application to a stiffened composite panel under compression is presented in order to point out the sensitivity of the impact damage resistance to the level of load. Finally, indications on a novel approach, able to take into account the non-linearity of the composite stiffened panels' response, are given.