THE EFFECT OF TARGET THICKNESS ON THE BALLISTICBEHAVIOR OF HYBRID CFRP/KFRP COMPOSITES

To achieve structural lightweight and sufficient containment capability, the use of hybrid composite stocivil aircraft engine cases is a major trend. One important but neglected topic was investigated that the thickness effects of hybrid carbon/Kevlar fiber-reinforced epoxy laminates on ballistic impact properties. Based on the results of ballistic impact tests, the finite element models of ballistic impact on carbon/Kevlar hybridlaminates were established using a progressive damage constitutive model, considering different thicknesses, impact faces and layering sequences. The results confirmed an extremely strong relationship between thickness and ballistic impact properties, which has never been addressed in any previous studies of composite stacking methods. Analyses further suggested that the C-K configuration, with CFRP as the impact surface and KFRP as the back surface, exhibits superior impact resistance when the thickness is relatively thin. Conversely, with thicker configurations, the K-C setup, where CFRP serves as the impact surfaceand KFRPas the back surface, demonstrates stronger impact resistance. This study provides theoretical support for the design and development of aero-engine cases.