Creep

Creep is the permanent elongation that occurs under continuous load, and is common for all gelspun UHMWPE fibres. Creep will increase with higher load as illustrated in figure 10 which shows permanent deformation of Dyneema® ropes. Creep factor is higher for SK75 fibres than for SK60 in relation to maximum breaking load. As the SK75 fibre is considerably stronger than SK60, the deformation or creep will be similar for both fibres in a rope of same diameter.

Creep has two important effects in ropes. Loads will equalize between the different yarns, thus rope strength will increase in use. Secondly, it can be used to estimate the safe working life of a rope. In addition to permanent deformation or creep, a higher elongation will occur in a new rope while the fibres or rope adapt to the structure of the load.
A worked rope or pre-stretched rope will therefore show less elongation than a new one. As the rope is put under tension for the first time, the fibres rearrange to provide better load sharing, resulting in a gain in the breaking load of 10%.

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