Tensile properties for netting materials used in aquaculture net cages

Structural analysis of aquaculture net cages in current

“…In M1, strains in the netting were up to 3% in the twines above the weights, while most of the netting had strains less than 10 À4 . The assumed value of 82 MPa represents the uniaxial stiffness of the netting materials, which can be applied for netting in net cages, as one load direction often dominates over the other for significant stress levels (Moe et al, 2007). The numerical analysis results showed that in the area with highest loads (upper part of the upstream side of the cage), the initially vertical twines were strained approximately 10 times as much as the initially horizontal elements.…”

“…The stiffness of the netting material was chosen as 82 MPa, given for a specified pretension in Moe et al (2007). This simplified netting material model was found sufficient for these global analyses (see Section 4).…”

“…Model M1 was similar to the cage without bottom subjected to model tests in a flume tank. Twine thickness, t, and half mesh width w 1/2 (ISO, 2002) were increased by approximately 8% compared with given values in Lader and Enerhaug (2005) in order to account for expansion due to water absorption (Moe et al, 2007). The solidity was calculated as Sn =2t/w 1/2 .…”

Determination of mesh breaking strength of polyamide fishing nets under the exposure of different heavy metal concentrations and temperature

“…Modern fishing has developed through three main technological revolutions such as development of mechanization, fish finding equipments and netting material (FAO 2005;Ramos 1999;Sainsbury 1996). The netting materials are usually produced of knitted bundles of multifilaments (knotless netting) or twines of twisted multifilament bundles that are connected by knots (knotted netting) (Moe et al 2007).…”

“…Most net cages are made of square mesh knotless Polyamide (PA) netting and Polyester (PES), Polyethylene (PE), Polypropylene (PP) and Polyvinyl alcohol (PVAA) ropes (Ramos 1999;Klust 1982;Moe et al 2007). PA continuous filament netting yarns have the highest wet knot breaking strength, followed by PP, PE and PES, while PVAA, PVC (Polyvinyl chloride) and PVDC (Polyvinylidene chloride) are too poor in this respect to be eligible for bottom trawls (Klust 1982).…”