Experimental investigations on the fatigue behavior of thick center cracked aluminum plates (10 mm) bonded
with two-sided composite patches were conducted. Fatigue tests indicated that fatigue life of two-sided repaired
specimens is 31 times greater than that of unrepaired specimens. The stress intensity factors (SIF) were calculated by using three-dimensional fi nite element method (FEM), which provide foundations to the prediction of
fatigue life of two-sided repaired specimens based on Paris' law. Predictions are in good agreement with the
experimental results.