Technical paper: Creep rupture and time to failure in para-aramid yarns

Para-aramid yarns under sustained load fail through creep rupture, a mechanism in which irreversible elongation accumulates until the yarn breaks. The load-lifetime relationship is non-linear: a small increase in sustained stress reduces time to failure by orders of magnitude. This behavior determines the serviceable lifetime of aramid fiber in long-life applications including ADSS cables, mooring lines for floating wind platforms, reinforced thermoplastic pipes (RTP), submarine power cables, flowlines, and umbilicals.

Teijin Aramid's Research and Innovation Center in the Netherlands has been testing creep rupture and measuring time to failure across our para-aramid product range for over 30 years. At a sustained stress of 1.81 GPa, Twaron® 2200 is predicted to last 30 years. At equivalent loads, Twaron® 2200 lasts 10 to 1,000 times longer than the majority of competing high-modulus para-aramids.

This paper presents the methodology behind Teijin Aramid's time to failure testing program, the long-term performance data for Twaron® 2200, and a framework for applying creep rupture data to aramid fiber lifetime prediction and application design.