Geometry and damage effects in a composite marine T-joint

The structural integrity and damage tolerance of typical composite T-joints found in ships constructed from glass fibre reinforced plastic was the subject of this investigation. The effect of the geometry of the T-joint on the strain distribution was investigated using finite element (FE) analysis. The results, reported in this paper, showed that the critical strains were significantly affected by the joint geometry. Results of the FE analysis conducted to investigate the effect of disbonds between the filler and overlaminate are also reported. This showed that particular defects led to large changes in the strains in the T-joint structure, which would encourage disbond progression. The FE model was validated by mechanical tests on a representative T-joint, instrumented with surface strain gauges and displacement transducers, into which a range of defects was progressively introduced.