Failure of CFRP airframe sandwich panels under crash-relevant loading conditions

Multiscale Modeling Methods for Analysis of Failure Modes in Foldcore Sandwich Panels

“…For the validation of the core trigger concept, quasi-static tests were conducted with the only difference of a local modification of the fold pattern for triggering. The experiments confirmed that the position of failure can be controlled by a local weakening of the core compression strength [17]. Additionally an explicit micromodel simulation approach was developed to numerically investigate the panel response under various loading condition [18].…”

“…For a CFRP fuselage a controlled progressive predefined crash kinematics is seen as necessary to obtain an equivalent crashworthiness. Experiments showed that failure initiation of a twinwalled fuselage panel can be controlled by a local modification of the core pattern [17]. The foldcore pattern used in the studies consists of a zick-zack pattern with additional integrated horizontal edges.…”

“…In the literature a representative bending to compression ratio of A=200 mm can be found for the investigated frame segment [17]. Therefore the functionality of the core trigger concepts was investigated under this representative loading condition.…”

“…1 Geometrical description of the fold pattern for the triggered and the untriggered region [17] simulations were performed using the implicit solver ANSYS 12.1. The described modelling method is validated using experimental test results of foldcore sandwich panels under combined compression/bending loads [17].…”

“…Virtual material characterisation tests were performed on a representative number of unite cells (3 times 5) using the explicit solver PAM CRASH V. 2009 [7,17]. For the investigation of the core behaviour under bi-axial loading, a defined load was applied on the core in a first load step.…”