Increasing demand for synthetic fibre ropes within Marine, Oil field, Civil Engineering and Defence applications has brought about the need for viable non destructive testing, NDT techniques. Current ND methods for wire rope can detect either overall changes in rope properties or local damage such as wire ' breaks No distributed measurement methods exist and no successful NDT methods of any form exist for fibre rope. It is well established that wire and some fibre hawsers give prior indication of incipient failure by changes in modulus. Overall modulus monitoring can predict such failure on short test lengths, typically of 2 to 1 metres but is inadequate for detecting local changes in modulus over, say, 10 metres in 1 kilometre of rope. OSCAR aims to use Optical fibre sensing methods. which provide information as a function of linear position, to detect and localise the initiation of rope failure. Two techniques in particular are consider to have the greatest potential. Optical Time Domain Reflectometry, OTDR, measures optical transmission loss as function of position and represents an ideal solution provided that the strain experienced by the rope can be made to modulate the fibre loss. Alternatively Brillouin scatter OTDR directly records the fibre strain but is more expensive to implement. Both approaches will be assessed from the viewpoint of cost, measurement capability and practical difficulty of implementing measurements in the field.
Funding SchemeEAW - Exploratory awards