Mechanical behaviour of HMPE and aramid fibre ropes for deep sea handling operations

Autor: Yvan Reaud, Peter Davies, Patrice Woerther, Loic Dussud
Rok vydání: 2011
Předmět:
Zdroj: Ocean Engineering (0029-8018) (Pergamon-elsevier Science Ltd), 2011-12, Vol. 38, N. 17-18, P. 2208-2214
ISSN: 0029-8018
DOI: 10.1016/j.oceaneng.2011.10.010
Popis: This paper describes the mechanical behaviour of ropes used for deep sea oceanographic operations. First the requirements of deep sea handling ropes are presented. Two high performance fibres are commonly used, aramid co-polymer and high modulus polyethylene (HMPE), and these are then compared. Results from tests on single fibres and 50 ton break load braided ropes are presented, which show that the initial stiffness of a new HMPE rope increases with load level in a bedding-in process resulting from both molecular alignment and construction reorientation. The aramid rope is less sensitive to this effect and shows a high stiffness from first loading. Measurements made at sea on oceanographic ropes of both materials using an elastic recoil method are presented, and apparent modulus values are consistent with laboratory measurements. Once both ropes have been fully bedded-in the HMPE is significantly stiffer, particularly under dynamic loads. Creep tests indicate that aramids creep less quickly than HMPE under constant loads over a 6 h period at 20 °C. Bending over sheave tests indicate longer lifetimes for the aramid but further tests on wet aramid are required to complete this conclusion. Highlights ► Original data on the mechanical behaviour of two types of deep sea handling rope. ► New results from measurements at sea. ► A discussion of the relative merits of aramid and HMPE fibre ropes for this application.
Databáze: OpenAIRE