Objective
The aim of the project was to characterise the behaviour of composite joints to a level where they could be designed without the need for specific structural testing. Furthermore, it would be possible to reappraise existing composite joints (such as leg joints in jackets with insert piles).
The specific objective of the project was to derive parametric equations for composite joints over a wide range of geometries.
Detailed and systematic analysis of the very large volume of data generated during the tests was undertaken with the aid of computers. The following findings were made :
STATIC STRENGTH
Under almost all loading regimes, significant strength improvements results form 'compositising' a tubular joint.
Parametric formular have been developed to relate the ultimate strength of a composite joint to its geometry. Characteristic formulae have also been derived.
FATIGUE PERFORMANCE
Compositisation leads to reduced stress concentrations at the critical hot spot locations under most loading regimes and this leads to an increase in fatigue life. Improvement in life expectancy of a joint can be 10 times or greater.
DESIGN STUDIES
Preliminary design studies undertaken by Wimpey show that potential savings fron designing new structures to incorporate composite technology outweigh the obvious savings in steel weight and fabrication effort.
The project was devised in 4 phases as follows :
Phase 1 : outline design studies and definition of testing programme.
Phase 2 : testing of composite components.
Phase 3 : development of analytical techniques.
Phase 4 : design studies.
The bulk of the spending was on Phase 2; in line with design practice for unreinforced tubular joints it was decided to base any new design parametric formular on results of physical tests on modesl of a realistic scale.
Some 86 specimens were tested in all.
On completion of elastic testing, the joints were tested to identify their ultimate strength. 72 of the specimens were tested under qusi-static loading, either in bending, tension or compression, and 14 were failed by fatigue loading.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
London
United Kingdom