Compressive Strength Prediction of Carbon Fiber-Reinforced Pultruded Profiles including Realistic Volumetric Fiber Orientations

A compressive strength prediction method considering 3D fiber orientation distributions is developed. The method quantifies volumetric fiber orientations using the structure tensor image analysis method on X-ray computed microtomography data. The estimated fiber orientations are subsequently mapped to a finite element mesh. The finite element model is solved using a three-dimensional non-linear constitutive model implemented as a user-subroutine in Abaqus^TM. A model capable of describing the elastic-plastic behavior of fibrous composites and simulating strain localization in the form of kink bands. The compressive strength of a carbon-epoxy pultruded profile is predicted based on three volumetric subsets of the profile and compared with experimental obtained compression test measurements. The strength predictions of the three volumetric subsets are in the range of 16-42 % higher than the experimental results. It is argued that the experimental results do not represent the full potential of the material compressive strength due to stress concentrations at the load introduction and that the model predictions can describe a potential for the actual compressive strength of the carbon-epoxy pultruded profile.