抄録
Near threshold fatigue crack growth (fcg) rate was measured under a stress intensity range (△K)-normalized crack length (a/W) relationship, equivalent to that for a circumferential crack in a thick-walled finite-length cylinder (which is suddenly cooled inside). The tests were conducted fundamentally in accordance with ASTM E-647. The objective of the experiment was to verify the validity of the thermo-elastic analysis for the crack by the authors. Tentative results showed that the threshold intensity range for the thermal-stress equivalent △K-a/W relationship was close to that obtained from that by standard ASTM K-decreasing near threshold fcg test.
