Mechanical and open hole tensile properties of self‐reinforced PET composites with recycled PET fiber reinforcement

Abstract

ABSTRACTThe tensile strength of notched composites is an important factor for composite structural design. However, no literature is available on the notch sensitivity of self‐reinforced polymer composites. In this study, self‐reinforced recycled poly (ethylene terephthalate) (srrPET) composites were produced by film stacking from fabrics composed of double covered uncommingled yarns (DCUY). Composite specimens were subjected to uniaxial tensile, flexural, and Izod impact tests and the related results compared with earlier ones achieved on srPET composites reinforced with nonrecycled technical PET fibers. Effects of open circular holes on the tensile strength of srrPETs were studied at various width‐to‐hole diameter (W/D) ratios of the specimens. In the open hole tensile (OHT) measurements bilinear (yielding followed by post‐yield hardening) stress–strain curves were recorded. The srrPET composites had extremely high yield strength retention (up to 142%) and high breaking strength retention (up to 81%) due to the superior ductile nature of the srrPETs, which induces plastic yielding near the hole thereby reducing the stress concentration effect. The results proved that srrPET composites are tough, ductile notch‐insensitive materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43682.