Microcreep properties of carbon fiber reinforced resin composites

Carbon fiber reinforced resin composites are widely used in various fields because of their excellent performance. Since the resin matrix has viscoelastic properties, the composite material synthesized by resin also exhibits viscoelastic behavior. Creep is the most typical type of phenomenon in the viscoelastic deformation, so it is of great significance to study the microcreep properties for carbon fiber reinforced resin composites. Under different peak loads, the microcreep behavior of the resin matrix, interface and fiber for carbon fiber reinforced resin composites were analyzed by nanoindentation technique at room temperature. At the same creep time, the results show that the creep displacements of the fibers which are about 1/3 and 1/2 of the matrix under 2 mN and 10 mN. And the values of interfacial creep displacements are between the fiber and the matrix. The creep rate of steady state creep stage is less than 0.1%. The creep stress indexes of the matrix, interface and fiber are 3.6, 2.9 and 2.1. The first and second complex modulus and the viscosity of the dashpot and creep complicement for the matrix, interface and fiber were obtained using the Kelvin-Voigt model at different peak loads.