Evaluation of fibre rope properties for offshore mooring

Experimental study of the cyclic visco-elasto-plastic behaviour of a polyamide fibre strap

“…Experimental investigations were also conducted on onedimensional structures like mooring lines for offshore applications (Banfield and Casey, 1998;Fernandes and Rossi, 2005) or energy absorber ropes for worker security (Spierings and Stämpfli, 2006). But, little research deals with the visco-elasto-plastic behaviour of polymer fibres, in order to analyse the reversible and irreversible phenomena that occur simultaneously during complex loadings.…”

Applications of polyesters and polyamides in civil engineering

“…Besides, if well designed, axial compression fatigue does not occur and internal abrasion appears to be the cause of the loss of strength after millions of cycles. However, the fatigue performance of polyester ropes depends on different factors like, fi bre quality, rope construction, termination design and on cycle load history [76,78,82,86,92].…”

A creep–rupture model of synthetic fiber ropes for deepwater moorings based on thermodynamics

“…Synthetic fiber ropes were first proposed as mooring lines in the 1960s [1], and since then lots of studies have been conducted. In 1983, the first attempt that aramid fiber ropes are utilized as the main part of mooring lines was made, although it failed attributed to not considering the fiber axial compression fatigue [2].…”

“…For polyester and aramid mooring systems Nomenclature t time t 1 creep time t r total time of the creep rupture ε(t) total axial strain at time t ε ve (t) recoverable viscoelastic strain at time t (t), ij actual or nominal stress (t), ij effective (undamage) stress mass density Á specific entropy ϕ Helmholtz free energy q heat flux vector T temperaturē (m) (m = 1, · · ·, M ve int ; M ve int ≥ 1) viscoelastic internal state variables Q (m) thermodynamic conjugate forces associated with the viscoelastic internal state variables Y damage force c constant stress g 0 , g 1 designed to API 2SK safety factors, creep failure is not a typical design issue in the intact mooring condition [7]. However, for conditions which result in high fiber loads (greater than 70% of the fiber break strength) for a long duration, creep failure can be a concern [13].…”