抄録
The experiments were performed using transverse impact due to an aluminium bar on the center of the simply supported beams and plates which were made of plaster and examed the time dependence of impact load and the position and the time of crack initiation. The fracture stress of impact was estimated by combining the position and the time of crack initiation and the impact load with the theory of flexural motion of an infinite beam and an infinite plate. It was found that the fracture stress was almost equal to the tensile stress obtained from the static tensile experiment.
