In order to provide the basis data for broad use and safe design of carbon fiber reinforced plastic, this paper aims at investigating the fracture behavior on CFRP specimen composed of one directional fiber through three point bending test. On the basis of experimental result, the improvement of composite layer specimen can be secured with the other data to compare the existing specimen. The fracture behavior happened at the experimental procedure is investigated in this study. The maximum loads of 1200 N, 1700N and 1600N are shown respectively at the specimens with the layer angles of 30°, 45° and 60°. The highest load is shown at the layer angle of 60° among all specimens and the longest displacement is maintained until each of the layer structure is broken down. The fracture due to the force applied from the outside can be prevented by applying the result of this study to the real structure. As structural safety can be evaluated and anticipated through this study, it is thought that the safe design is devoted.

In this study, the buckling restoration at CFRP 3-Point bending specimen composed of 30°, 45°and 60° is investigated when the pressure at the lowest position on the compressed specimen is eliminated. The fracture configuration and stress contour of the specimen can be seen according to the laminate angle of fiber. The result of this study is thought to apply the data for the safe design of CFRP structure.