CFRP Fatigue Damage Detection by Thermal Methods

In this work, the fatigue damage of CFRP uniaxial composite specimens were studied using thermal methods to determine the fatigue behavior. The aim was to evaluate the fatigue damage as a function of the number of cycles. Consequently, the damage process was studied in terms of a global indicator, considering the stiffness decay, and in terms of local parameters, considering the evolution of temperature maps acquired during the fatigue tests. A direct correlation between the damage index, corresponding to 90% of the fatigue life, and the temperature variation of the most stressed area was found. Another parameter taken into consideration was the heating rate during the application of the first thousands cycles. This parameter was proportional to the stress amplitude, making it a useful parameter since it refers to the initial part of the specimen fatigue life.

Automated summary

This study investigated the fatigue damage of CFRP composite specimens using thermal methods, aiming to evaluate the relationship between damage and the number of cycles. The damage process was studied based on a global indicator, stiffness decay, as well as local parameters, such as temperature maps during fatigue tests. A direct correlation between the damage index and temperature variation in the most stressed area was found. The heating rate during the initial cycles was also considered as a useful parameter.