超音波振動を受けるクラックを有するクロスプライCFRP積層板の変分法による応力解析

抄録

Carbon fiber reinforced plastic (CFRP) laminates are expected to be expanded as structural members due to their excellent mechanical properties. It is essential to evaluate very high cycle fatigue properties to ensure long-term reliability and durability. However, conventional hydraulic fatigue test requires a huge amount of time, so accelerated testing by ultrasonic fatigue test using resonance phenomenon has been conducted. Since the stress distribution applied to the specimen is typically in the hydraulic fatigue test, but not in the ultrasonic fatigue test, it is necessary to obtain the stress distribution when transverse cracks occur in the ultrasonic fatigue test. In this study, the stress components of the CFRP cross-ply laminates with transverse cracks subjected to ultrasonic vibration were calculated by the variational approach considering thermal residual stress. As in the case of typically loading stress, the 90° layer stress decreased to zero at the location of the crack, and it was confirmed that the 0° layer stress increased by sharing the mechanical stress that the 90° layer carried.