Application of infrared thermography in fatigue life estimation of drilled CFRP laminates

Abstract

The application of non-destructive techniques to evaluate composite materials under fatigue is an area of growing interest within the scientific community. Among the available techniques, the use of infrared thermography stands out due to its affordability, simplicity, and promising results in previous research. In this study, infrared thermography is applied with the aim of obtaining predictive models capable of estimating the fatigue limit of thick CFRP (carbon fiber reinforced polymer) laminates subjected to tensile loads. Experimental tests involve monitoring the temperature in laminates with typical characteristics of the aerospace industry, using a thermal camera. The experimental campaign involves varying levels of damage due to drilling and cyclic tensile loads. With the data obtained from the temperature evolution during the initial phase of fatigue tests, predictive analytical models of the fatigue limit are obtained. The results indicate that the proposed model efficiently predicts the fatigue limit with high reliability, showing a strong correlation between predictions and experimental results. This underscores the utility of thermographic techniques for evaluating damage and predicting the fatigue limit of CFRP laminates under various loading conditions