Influence of bedding-in on the tensile performance of HMPE fiber ropes

Abstract

Synthetic fiber ropes are widely used in the maritime industry, with applications from sailboat rigging to offshore platform mooring lines, thanks to their numerous qualities compared to steel cables: light weight, good specific mechanical properties and excellent marine resistance. A key feature of these ropes is their sensitivity to loading history, as this affects subsequent performance. In the present work the influence of the maximum bedding-in load level and the loading path were studied at the different rope component scales (filament, yarn and braided rope), in order to develop an optimal bedding-in procedure for braided ropes. The load levels were: 10%, 30% and 50% of the tensile break load of the sample. From the results obtained, the influence of braid construction and material have been studied, and an efficient bedding-in process has been defined. It was shown that the main parameter is the maximum load level, the loading path is not important. The load required to bed in HMPE ropes is closely related to changes in the braid angle under load. Highlights► Unique results of the influence of bedding in protocol on at different rope scales. ► Influence of bedding-in loading path and loading level on tensile behavior. ► Correlation between fibers reorientation and bedding-in protocols. ► Separation of contributions from material and construction.

Experimental evaluation of the main parameters influencing friction between polyamide fibers and influence of friction on the abrasion resistance

“…This suggests a possible explanation for this observation: in the literature, it is well known that there is a rearrangement of fibers during a tension loading. Bain et al (2020) observed this phenomenon on fibers assembled in braided ropes. This assumption was also made by Liu et al (2006) to explain the evolution of the coefficient of friction with the yarn axial tension.…”

“…Several previous studies (Gassara et al, 2018;Leech, 2002) have noted that there are various fiber/fiber friction interactions, depending on their orientations, such as: longitudinal-to-longitudinal, longitudinal-to-transverse, transverse-to-transverse. Under mechanical load, fibers reorient (Bain et al, 2020), which changes the angles between the fibrous elements, and so this will also affect friction values (Leech, 2002;Lindberg & Gralén, 1948). In order to quantify this effect, published work has focused on the influence of the main parameters; the angle between fibers, and the tension in them.…”

The effects of preloading on tensile properties of braided polyarylate fiber ropes

“…This indicates that the fiber damage might not have occurred during the preloading process with 50% MBL preload level, which also is consistent with results of previous studies. 11,14…”

“…The efficient bedding-in process for braided UHMWPE ropes with load level at least to 30% break load. 11 Moreover, the modulus of braided UHMWPE fiber ropes was basically stable with one cyclic loading, because the unrecoverable structural elongation of the rope structure was eliminated during the first cyclic loading. 12 For large diameter ropes, 10,000 cyclic loadings should be applied to completely stabilize the axial stiffness due to it having larger strands and more complex fiber alignment.…”

Modeling of the cyclic visco-elasto-plastic one-dimensional behavior of polyamide-based woven straps

“…Dyneema, Spectra) braided loop; this reduces the weight and increases the robustness of the system. 10,11 (5) Some tires need fiber reinforcement; nylon, polyester or aramid cords are used. [12][13][14][15][16] (6) Manipulator or robot arms are designed, such that the transmission of the actuator loads to the parts of the arm is performed by aramid yarns.…”