斜交対称CFRP積層板の低サイクル疲労挙動に関する実験的考察 Experimental Observation on Low Cycle Fatigue Behavior of Symmetric Angle-Ply CFRP Laminate
Cyclic zero-tension tests for symmetric angle-ply CFRP laminated specimens were carried out to investigate the low cycle fatigue behavior of graphite/epoxy and graphite/PEEK composites. Two types of stacking sequences were tested: [+θ/-θ]<SUB>4s</SUB> (Distributed ply) and [+θ<SUB>4</SUB>/-θ<SUB>4</SUB>]<SUB>s</SUB> (Blocked ply), where θ was 30<SUP>º</SUP> or 45<SUP>º</SUP>. Stress-strain curves of specimens under cyclic loadings were obtained by means of an extensometer. A mechanical ratcheting, which means progressive increase in plastic strain at each cycle, was observed on the cyclic stress-strain curves. Comparing the stress-strain curve of static tensile test with one of the cyclic zero-tension test, we made the assumption that the fatigue failure occurred when the ratcheting strain by cyclic loadings reached the static failure strain. Results of an ultrasonic scanning test revealed that the distributed ply specimens differed from the blocked ply specimens in an internal fatigue damage progress.
- 日本航空宇宙学会論文集 = Journal of the Japan Society for Aeronautical and Space Sciences
日本航空宇宙学会論文集 = Journal of the Japan Society for Aeronautical and Space Sciences 54(635), 555-562, 2006-12-05