Abstract

The effect of the stress ratio on growth behavior of mode II interlaminar fatigue cracks was studied with unidirectional carbon/epoxy laminates, Toray T800H/#3631. The end loaded split (ELS) specimens were used for tests under negative stress ratios. For each stress ratio, the crack propagation rate was given by a power function of the stress intensity range, ΔKII, or the maximum stress intensity factor, KIImax, in the region of rates above 10-9 m/cycle. Below this power law region, there exists a threshold value of the stress intensity range, ΔKIIth, for the fatigue crack propagation. The value of ΔKIIth was constant for the stress ratio between -1.0 and 0.6. In the power law region, both ΔKII and KIImax affect tht crack propagation rate. The effect of KIImax decreases as the crack propagation rate decreases. In the near-threshold region, the crack propagation rate is controlled only by the ΔKII value ; the value of KIImax has no effect on the crack propagation. A simple equation was proposed for predicting the propagation rate of mode II fatigue cracks under various stress ratios. Predictions agreed well with the experimental results for both positive and negative values of the stress ratio. The effect of the stress ratio on propagation mechanisms of fatigue cracks was discussed on the basis of fractographic observation.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.