穴または圧こんの付加による板材の疲労き裂伝ぱ遅延効果

抄録

This paper is concerned with the beneficial effects due to additional holes or indentations. Two indentations facing each other with the tip of a crack is especially effective in retardation of crack propagation. The effects of the indentations can be estimated approximately from the existence of residual stresses produced by the indentations.