抄録
Impact tension was applied to a PMMA (polymethylmethacrylate) strip specimen with a notch. An inclined notch was introduced by milling specimens before the experiments. The fracture strains ε_<nf> and ε_<sf> were measured near the notch root and at the smooth portion, respectively. The strain concentration factor defined by the ratio K_f=ε_<nf>/ε_<sf> was a constant to the inclination angle of notch, θ The factor K_e of the short specimen in the elastic region was larger than that of the long one. The impact strength of the strip with a notch could be estimated by the strain rate near the notch root.
