Abstract
Using sheet electron beam (EB) irradiation, reinforcement for carbon fiber was achieved. In order to annihilate twisting strain in carbon fiber, fracture stress was precisely obtained by means of a twisting free tensile test developed. The EB treatment enhanced the fracture stress at different integrated fracture rates (R_f) and increased Weibull modulus. It also enhanced design stress, when the integrated fracture probability (P_f) is (10)^<-5> for aircraft materials. The aircraft design stress was approximately 4 GPa larger than that before EB treatment.
