き裂進展抵抗曲線(J_I-R曲線)に関する考察

概要

論文の詳細を見る
Stable crack growth experiments for SM 50 A steel and 2017-T3 aluminum were carried out to obtain J_I-R curves under crack-line wedge loading and 3-point bending. J-integral value, which was computed by use of the formula for a growing crack recommended by ASTM, increased at different rates with the crack growth amount under both type loadings while the values at initiation equaled. Finite element analysis was made for the stable crack growth measured by the experiment to compute the J-integral value at the growing crack tip. In elasto-plastic materials, elastically unloaded region is left behind the growing crack tip. This region lets J-integral lose the path independency. J-integral value at growing crack tip was computed from the integration of J along the specimen outer contour and correction for the unloaded region. The computation results showed that the J-integral value at the crack tip was almost invariable while the crack grew and was independent of the loading type.
1985-01-25