The Estimation of Fracture Resistance of Orthogonal Three-Dimensional Fiber-Reinforced Composite by DCB Testing

Abstract

The degree of the enhancement of the fracture resistance of an orthogonal three-dimensional composite of carbon fiber reinforced epoxy is experimentally determined using a DCB testing method. By analyzing the load-displacement curve and the energy change caused by the breaking of the bridging fiber yarn, the mechanism of the bridging enhancement of the fracture resistance is considered. It was found that the greater the number of bridging yarns in the crack, the greater is the amount of deformation energy per cracking area necessary for crack propagation. An estimation method for the mode I fracture toughness of the material is presented.