Compression Strength Prediction of Unidirectional Carbon Fiber Composites Using a Mesh-Objective Homogenization Model and Real Fiber Orientation Distribution

This work introduces a methodology for numerical predictions of the compressive strength of unidirectional composites with realistic fiber orientation distributions, which were obtained via structure tensor analysis of 3D X-ray computed tomography scans of specific carbon fiber-reinforced polymer samples. Experimental characterization was performed on the material properties of the constituents, as well as the actual composite. The extracted fiber orientation distribution and the material parameters of the constituents were implemented in a two-dimensional finite element model. The model performs mesh-objective material homogenization for the fibers and matrix constituents, in which the fiber diameter defines the characteristic material length scale. The numerical prediction of the compressive strength was compared with experimental measurements. A kink band-driven failure mechanism was predicted by using the finite element model. The results show that the model can predict the compressive strength potential of the pultruded material, while accounting for the actual distribution of fiber orientation.