Damage of FRP Plates Containing Sharp Notches or Blunt Notches

Prior to catastrophic fracture for notched FRP plates under static load, the damage appears and grows neaer the notch root. The validity of the failure criterion based on idea of severity near the notch root for evaluating the damage of notched FRP plate is investigated experimentally in this paper. An experimental method is presented which examines the effect of notch geometry on the initiation and growth of the damage near the notch root of FRP plates subjected to tension. The investigation was accomplished by obtaining experimental data on the tension test of a glass fiber-reinforced polycarbonate plate containing notches for wide range of notch geometries. To evaluate the damage near the notch root, we measured successively the luminance distributions by means of the luminance measurement technique with a CCD camera. The experiment shows that the process of the initiation and growth of damage near the notch root is determined by both the maximum elastic stress and notch-root radius for sharp-notched specimens. On the other hand, for blunt-notched specimens, the process of the initiation and growth of damage is determined by the terms of a combination of the maximum elastic stress, notch-root radius and width of notch section. On the basis of the idea of severity near the notch root mentioned above, the experimental results can be explained.