Fracture Criterion of Notched Plates of FRP

Abstract

The influence of notches on the static tensile strength of plates was studied for a composite material. Tension tests on notched plates made of fiber glass/epoxy laminates have been carried out for a wide range of notch root radii. All notched specimens failed in a brittle manner through the formation of a small deformation near the notch root. This experiment shows that the nominal stress at failure decreases with decreasing notch root radius, and it approaches a constant value when the notch root radius is less than about 0.2 mm. It has been verified that the maximum elastic stress at the notch root when the specimen fails is governed by the notch root radius alone and is independent of notch depth. On the basis of the concept of linear notch mechanics, the experimental results mentioned above can be clearly explained, and the limiting condition for the fracture of notched plates of composite materials is determined. This condition is the same as that of notched engineering plastics.