The crashworthiness prediction of 2D triaxially braided composite fuselage frame under transverse impact load

The fuselage frame, an apron construction of the typical transport aircraft fuselage, manufactured with carbon fibre/epoxy 2D triaxially braided composites, hinders the crashworthy aircraft analysis and design for the complicated failure behaviour under transverse impact loading. To capture the intricate details, the crashworthiness performance is investigated and compared with different damage models including enhanced composite damage model, composite failure shell model and laminated composite fabric model. Based on the continuum damage mechanics and irreversible thermodynamics, the progressive failure behaviour is implemented to predict the damage behaviour. The damaged constitutive equations with damage state variables and Hashin's criteria are adopted. Results show that the presence of non-physical parameters in the damage models make it challenging to predict the peak and post-peak responses using enhanced composite damage model and composite shell failure models. The laminated composite fabric model demonstrates good functionality to capture the failure sequences and the load response of the frame under transverse impact loading.