An Investigation on Creep and Creep-Rupture Behaviors of HMPE Ropes

Creep tests of high modulus polyethylene (HMPE) samples are performed to obtain the corresponding creep and creep-rupture curves. The results show that the secondary creep stage is especially pronounced, and its creep rate is nearly constant. Based on this fact, the creep rate at the secondary stage has been utilized as the representative value of each case. Therefore, the similarity criterion of creep rate at secondary stage is proposed to analyze the corresponding relationship between engineering creep rate and that in laboratory tests. Besides, an empirical expression of HMPE yarns is proposed to account for the effects of both loading level and test temperature on the creep rate at the secondary stage. Moreover, an equation for calculating the creep lifetime of HMPE samples is derived and verified by test data. This study will help to improve the understanding of creep behaviors of HMPE ropes and provide a significant reference for the application of HMPE ropes in mooring engineering.