Effect of mesoscopic out-of-plane defect on the fatigue behavior of a GFRP

This paper deals with the influence of buckles that are a mesoscopic out of plane defects on the fatigue behavior of a GFRP. Three cases were investigated: Healthy samples with no defect and specimens with buckles defects that are first generated in the longitudinal direction and then on the transverse direction.. First, static tests were used to measure the differences of the mechanical properties of both defect orientations and, thanks to digital image correlation, to see where were localized the areas of maximal local strain on the samples. Secondly, fatigue tests were performed in the three configurations. The results revealed that both defect orientations have a significant effect on the fatigue life and on the strain field. The configuration with defects in the transverse direction is the most crippling condition as expected from the static tests but the longitudinal direction configuration was also very affected by the presence of the mesoscopic defects. Those observations lead to conclude that this mesoscopic out of plane defect has a major negative influence on the fatigue life of such a composite.