EurOCEAN 2000 - Vlaams Instituut voor de Zee

tools will be directly compared to the respective data measured in the experimental tests of the
small and large cylinders/domes. In addition, a novel modelling technique will be used to
optimise the filament winding angles and stacking sequences for each thickness of cylinder to
be fabricated.
Fabrication of the cylinders will be carried out by two of the participating organisations to
establish the best practice and to identify/solve practical manufacturing problems. Each
cylinder will be dimensionally and non-destructively (ultrasonic) inspected to establish quality
and detect any internal flaws (delamination). Experience gained in the fabrication of the small
cylinders will be fed directly into the manufacture of the final large-scale demonstrator
cylinder and the design and fabrication guidelines. The large-scale domes will be manufactured
by the resin transfer moulding (RTM) process, while the small-scale domes will be fabricated
by filament winding.
Axial compression tests will be carried out on a number of the small-scale cylinders. These will
then be subjected to a hydrostatic pressure test up to failure with either metallic flat end plates
or small composite end-domes. A number of the small composite end-domes will be tested
individually prior to the fabrication of a matched dome/cylinder combination. A set of the large
RTM domes will be tested, back-to-back, to establish their performance before a set is installed
on the demonstrator cylinder.
In addition, a number of small-scale cylinders with flat end plates along with a large-scale
cylinder and a set of large RTM domes will be deployed at sea at a depth of 2,000 metres for a
period of twelve months. Each cylinder will be internally instrumented with battery powered
data loggers which will collect and store strains for a period not less than 450 days. This will
provide basic information on the creep properties of the composite material, the long-term
stability of the construction (interface rings, seals etc), the interaction of different materials and
water absorption.
The final test will be of an all composite demonstrator AUV designed to a working depth of
2,000 metres with a nominal factor of safety of 1.5. Failure pressure should therefore be in
excess of 3,000 metres (300 bar).
In addition to the theoretical modelling and experimental tests the project will:
- draw up a statement on the functional requirements,
- identify potential applications/markets for the technology,
- promote the commercial exploitation of the technology.
The emergent design methodology arising from the work as a whole will provide vital
information that may be used by engineers to help clarify and meet customers’ requirements
for pressure resistant structures in mid-water and benthic applications.
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