An approach for predicting fatigue life of CFRP retrofitted metallic structural details

This paper presents a new approach to estimate the fatigue life of metallic details retrofitted with bonded CFRP patch. Existing phenomenological and analytical methods to predict the fatigue life of metallic structural details retrofitted with bonded CFRP patch do not consider the cyclic degradation of the composite patch. As for all materials the composite patch (CFRP and adhesive) will experience degradation during fatigue cyclic loading. In this regard, a new approach that takes into account the fatigue cyclic degradation of the composite patch is proposed in this paper by introducing in the fatigue damage accumulation model of the metallic element, a cycledependent stiffness degradation parameter of the composite patch. The stiffness degradation parameter is obtained using a fatigue stiffness degradation model calibrated from experimental fatigue data of CFRP adhesively bonded double strap joints. Experimental data available in the literature of central hole aluminium plates bonded with CFRP are utilized for validation of the approach.

Automated summary

This paper presents a new approach to estimate the fatigue life of metallic details retrofitted with bonded CFRP patch, taking into account the cyclic degradation of the composite patch.