Multiscale mechanical property prediction of unidirectional fiber-reinforced composites containing resin-deficient defects

A prediction model for mechanical property of composites with resin-deficient defects was established. Based on the homogenization theory, the characteristic parameters (volume fraction) of the resin-deficient defects were introduced into the Chamis equation, and the equivalent mechanical property solutions of these composites were deduced. In this way, the prediction models for the mechanical properties of composites with resin-deficient defects were developed, and the theoretical calculation were compared with the simulation data and the reported testing data. The maximum prediction errors of elasticity parameter and strength parameter are less than 9% and under 12%, respectively, and the errors from the experimental data are below 4%. With the model above, accurately forecasting the mechanical properties of composites with resin-deficient defects is highly feasible. The transverse elastic modulus and shear modulus are more sensitive to the resin-deficient defects in the composites. Even if the content of resin-deficient defects is small, the defects will remarkably influence the transverse tensile and shear strengths. The general changing trend of elasticity and strength parameters drops with the rising level of resin-deficient defects.