Influencing Factors on the Longitudinal Compression Properties of Pultruded Unidirectional Fiber Composites

Abstract

Unidirectional fiber composites produced by pultrusion have good mechanical properties. We conducted compression experiments to investigate the factors that influenced the compression of pultruded unidirectional carbon fiber-reinforced plastics (CFRPs) under static axial loads. The CFRPS were composed of carbon fiber or carbon fiber cloth as reinforcement material, resin, ceramic, metal, cement, carbon or rubber as matrix. The modulus and compressive strength were measured. The experimental data were compared with the theoretical values obtained from the rule of mixtures. Moreover, the effects of the components, dispersion, interface states, and other factors on the compressive mechanical behaviors of the composites were studied. Scanning electron microscopy revealed the microstructure and fracture of the material. The results showed that the modulus and compressive strength of the CFRPs with a higher carbon fiber modulus decreased with the modulus and resin strength. The compressive modulus and compressive strength of CFRPs with the same resin increased with the modulus and strength of the carbon fibers. Upon increasing the modulus and strength of the carbon fibers, the compressive modulus and compressive strength of the CFRPs decreased with the modulus and strength of the resin. Moreover, glass fiber-reinforced plastics (GFRPs) were used to compare the difference between CFRPs, C/GFRP, and GFRP. The relationship between the the microstructure and promperties of these composites was systematically revealed. These research results are valuable for the design and synthesis of low-cost pultruded unidirectional fiber composites with excellent mechanical properties.