Fluid – structure interaction study for the DIFIS System’s composite riser tube

Abstract

DIFIS System was developed for oil recovery from shipwrecks and for the elimination of the pollution threat during EU FP-6 framework. The installation time’s reduction in cases of environmental pollution is a crucial factor for DIFIS system design. In the current work, the polyethylene riser tube parts (15 meter) of DIFIS System was replaced by a composite riser tube parts (30 meter) succeeding lower installation time for the DIFIS’s riser. The analysis and development of composite riser was based on the verified 2 – way fluid structure interaction (FSI) results from polyethylene riser. A methodology based on polyethylene riser’s normal modes (target values) was proposed and the composite riser’s structural integrity was investigated in order to reach these target values. The normal modes analysis and the 2 – way fluid structure interaction simulation were performed in ABAQUS software. The composite riser’s dynamic response under sea current is significant better than polyethylene riser (lower displacements in both axes, parallel and vertical to flow). In overall, the time reduction of the DIFIS’ risers installation by 40% was achieved, using longer riser parts.

Failure study of the woven composite material: 2.5 D carbon fabric/ resin epoxy

“…In order to conduct a failure simulation of the composite G1151/Resin epoxy, a simple coupon simulation test has been carried out, the present method was carried out by several authors [32][33][34]. The dimensions of the composite virtual coupon were 20 x10 x 1 mm, which represent a small volume of the material under uniaxial stress.…”