Mechanical behavior of PET fibers and textiles for Stent-Grafts using video extensometry and image analysis

In this paper, two kind of polyethylene terephthalate fibers and two woven textiles, taken from endovascular Stent-Grafts were analyzed by tensile tests. A non-contact video extensometer was used, which allowed precise strain measurements on material test samples. The technique used, allied with yarns image analysis, allowed to determine the yarn and textile stresses and to study their elastic/plastic deformation with much more accurate properties measurements. It was observed that the textiles present an anisotropic behavior although the textiles present similar weaving in the two woven directions. The yarns specimens were also analyzed by differential scanning calorimetry in order to study their crystallinity ratio, when subject to different stress levels. The properties measured are important for future performance analyses by finite element modeling and for defining improvements in devices design.