Comparison of failure criteria application for FML column buckling strength analysis

The paper presents the results of the comparative analysis of failure criteria application to Fibre Metal Laminate (FML) profiles loading assessment which concerns a hybrid composite consisting of alternating thin layers of aluminium and fibre-reinforced epoxy. In particular, it was Tsai-Wu, Hashin and Alfred Puck criteria implemented for thin-walled open cross-section profiles subjected to uniform compression. Due to the GFR epoxy presence the structure is considered as thin-walled orthotropic plate but of transversely isotropic symmetry in plane perpendicular to fibres. The discrete model was created to estimate the buckling load and load carrying capacity of the structure and obtained numerical results have been compared with the experimental evidence. Further implementing of real parameters and strengths of the material obtained in laboratory tests allowed one to estimate the potential failure of the structure in the buckling and post-buckling state. Failure factors were determined for each layer separately in order to distinguish the position greatly exposed to damage. Detailed analysis was also performed to assess the growth of failure factors in various wall locations determined for different load steps. However, FC results differ mutually and therefore the stress tensor components and their participation in the FML failure mode was also investigated.