Experimental and numerical study of the fatigue behaviour of composite patch reinforced cracked steel plates

One-side, low cost carbon/epoxy patches were laminated on large scale specimens, which were tested and subsequently modelled with the finite element method. An R = −1 cyclic loading was applied and patch strains and crack propagation rate were monitored. The experimental results were very encouraging, demonstrating that patches can effectively slow down the crack growth and extend the specimens’ life by a factor of up to 2, despite their relatively low stiffness ratio. Based on some simplified assumptions, FE modelling proved adequate in accurately predicting the crack propagation rate.