Fracture of FRP plates containing a circular hole under tension.

Abstract

A fracture criterion developed previously for predicting the uniaxial tensile strength of composite laminates containing notches is subjected to further experimental scrutinization. An experimental program is presented which examines the hole size effect in fractures of FRP plates. This is accomplished by obtaining experimental data on glass cloth-epoxy laminates containing through-the-thickness circular holes for a wide range of hole and specimen sizes. In the case that the ratio of hole size to the specimen width is less than 0.25, the maximum elastic stress at the edge of a hole when a specimen fails is governed by the hole size alone, and is independent of specimen width. 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 FRP plates containing a circular hole is expressed. The condition is the same as what is exprssed in the case of FRP plates containing notches.