Experimental and numerical investigation of patch effect on the bending behavior for hat-shaped carbon fiber composite beams

Abstract

Abstract In this study, reinforced composite panels with hat-shaped profile were produced from woven carbon fiber fabrics by vacuum infusion method. Holes were drilled on the crown surface of these panels and repaired with composite patches. The mechanical behavior was examined by performing a three-point bending test on the obtained patched and unpatched specimens. The contribution of the repair to the failure load of the damaged specimens under bending load has been clearly determined. In the numerical part, Hashin damage criterion was used for the beginning of damage. For damage progression, both Continuum Damage Mechanics and Material Property Degradation methods were preferred and compared. In the analysis carried out using the finite element package program Workbench, the cohesive zone model (CZM) was added to the model and its effect on the damage behavior and load of the composite structure was determined. As a result of the experiments and analyses, it was seen that the maximum contact force of the specimens under the bending load decreased by 29.8 % by increasing the number of holes on the specimen surface from 1 to 3. The maximum contact force was determined to increase by 18.52 % due to repairing the three-hole specimens with a patch.