Rapid fatigue life estimation of drilled CFRP laminates and titanium stacks using thermography

In this work, we estimate the fatigue life of drilled Carbon Fiber Reinforced Polymer (CFRP) laminates making use of the temperature evolution of the component. As the self-heating effect due to cyclic loading causes a temperature change in the initial stages of the loading, the slope of the temperature variation Δ T versus the number of cycles can be used to estimate the remaining life. We have validated the applicability of the procedure for drilled laminates under different cutting conditions, and for drilled Ti-CFRP stacks. Infrared thermography was used to obtain the temperature variation during cycling loading. The results proved that the obtained adjusted model can effectively estimate the fatigue life of CFRP laminates with delamination damage or thermal damage with an error of 15%, proving the usefulness of this methodology for drilled and stacked laminates.