Fatigue par flexion de composites unidirectionnels a renfort verre

摘要

The flexural fatigue behaviour of GFRP beams has been analysed in the light of a stress corrosion cracking model. This approach was developed in the context of unidirectional glass/epoxy composites, where the initial fatigue damage is known to be mostly associated to the delayed failure of the fibres. Theoretical expressions for the stiffness loss have been derived, which require the determination of the statistical distribution of fibres strength and the assessment of the sub-critical-crack growth rates within the glass filaments. From stiffness loss measurements under monotonic and static fatigue conditions, consistent values of the Weibull modulus, m, and the stress-corrosion parameter, n, have been obtained. These values were successfully used in the model to predict the experimental stiffness loss of the composite beams under cyclic fatigue conditions.