EFFECT OF MOISTURE ON A FATIGUE CRACK FOR ADHESIVELY BONDED JOINTS -PSEUDO THRESHOLD AND SECONDARY CRACK GROWTH-

摘要

(1) The fatigue crack growth resistance increases due to both sulfuric acid and c-sulfuric acid treatments. (2) In cases of both acid treatments, the pseudo-thresholwhere the crack once stops growing with decreasing AG/, appears under the laboratory environment. This phenomenon does not appear under the dry environment. However, in the case of acetone cleaning, the fatigue crack growth behavior under the dry environment is almost the same as that under the laboratory environment. The crack does not arrest before reaching its final threshold. No pseudo-threshold is distinguished.