抄録
The tensile test was conducted on the FRPA with the crack initiated by the fatigue test, including fiber content in weight of 50% made by direct injection molding method. The relation between the fractal dimensions obtained from the AE amplitude distributions, the damage (white) zone at the crack tip, the microfractographs analysis and the strain energy were examined during the process of its tensile test to fracture.
The fractal dimensions obtained from the AE amplitude distributions of fatigued specimens became lower when the stress amplitude and the number of cycles became higher. The microfractographs analysis showed that the specimens of the higher fractal dimensions had fracture surfaces of larger roughness, but the ones of the lower fractal dimensions had fracture surfaces of smaller roughness. It was found on the fatigued specimens of the region II where AE was detected constantly that the fractal dimension obtained by normalizing the experimental values of fatigued specimens with the experimental one of non-fatigued specimen decreased with a decrease in the normalized strain energy.
