CFRP積層板の引張負荷におけるマトリックスクラッキングと残留ひずみ

抄録

Matrix cracking in CFRP laminates results in the mechanical property degradation of the material such as stiffness reduction, the existence of residual strains, etc. Usually, the damage parameters used for matrix cracking are stiffness reduction, Poisson’s ratio reduction and the change in thermal expansion coefficients. In this study, a damage parameter, the existence of residual strains, is experimentally and analytically investigated for CFRP [0/75₆]_s laminates. Due to very small residual strains at the unloading condition, the residual strains have also been measured at other different stress levels for laminates with different crack densities and are compared with theoretical predictions. Laminates’ time-dependent viscoelasticity behavior of the residual strains is also considered so that only residual strains due to the occurrence of matrix cracks can be accurately measured. The experimental results of the residual strains are in reasonably good agreement with the theoretical predictions.