1968 年 17 巻 176 号 p. 408-414
A repeated impact tension testing machine was designed by means of which a single pulse stress wave was made to pass through a specimen under one impact loading. By making use of it, the repeated impact strength of 0.01% C steel was investigated, and it was found that the failure and fracture of the material were influenced not only by the stress magnitude but also by its duration. The main test results are as follows. (1) The yielding occurred near both the ends of the specimen and the yielding zone spread toward the center with each passage of stress wave. (2) The total duration of stress required for breaking the specimen could be regarded nearly constant under the constant stress magnitude. (3) The elongation under repeated impact stress was larger than that under static tension.