The Fiber Volume Fraction (FVF) is a key parameter within the mechanical characterization of Carbon Fiber Reinforced Polymers (CFRP) at material level. An accurate methodology for the local determination of the layerwise FVF is required for a reliable and accurate analysis. In this study, a Fiber Volume Gradient Characterization Methodology is developed based on the Fiber Counting Algorithm for the layerwise determination of the FVF for angles up to 45°. For this, acid digestion, loss on ignition and the optical method are compared. While all investigated methods show high consistency, it should be noted that the optical FVF determination allows for localized FVF assessments while being subject to operator dependent image acquisition. Based on this comparison, an automated methodology is validated using optical micrographs. The developed methodology allows for a fast and accurate characterization of the FVF in layered structures and can therefore be applied to various structures in CFRP engineering. As an application example, the layerwise FVF of a Composite Pressure Vessel (CPV) is analyzed by the optical assessment and compared against the loss on ignition method, resulting in deviations below 1.05%.     «

The Fiber Volume Fraction (FVF) is a key parameter within the mechanical characterization of Carbon Fiber Reinforced Polymers (CFRP) at material level. An accurate methodology for the local determination of the layerwise FVF is required for a reliable and accurate analysis. In this study, a Fiber Volume Gradient Characterization Methodology is developed based on the Fiber Counting Algorithm for the layerwise determination of the FVF for angles up to 45°. For this, acid digestion, loss on ignitio...     »