Irwinの塑性域補正に関する一考察

概要

論文の詳細を見る
Plastic zone initiation by load at crack tips is considered to be one of the major topics of Linear Elastic Fracture Mechanics. The Irwin's Plastic Zone Adjustment is usually applied to the crack length. However, hardly any experimental verification has been performed on the adjustment of crack length. It may be said that one of the reasons for this is that it is very difficult to make an experimental measurement of plastic zone length. Recourse to the observation of yield stress patterns or Stretcher Strains would make it relatively easy to make experimental measurement of plastic zone size. Yield stress patterns were used to make experimental measurement of the lengths of plastic zones brought about by the application of a tensile load to a notch tip of rectangular tension test specimens made from carbon steel. The experimental results show that the experimental values of the plastic zones lengths approach more closely to the first approximate value than the Irwin's Plastic Zone Adjustment value do. It was realized that one of the reasons for this was a relation between the redistribution of singular stresses and the ductility of the experimental strip. The Irwin's Plastic Zone Adjustment should be construed as valid for the adjustment of plastic zone length only under certain conditions.
明治大学の論文