Akademik Veri Yönetim Sistemi
ADVANCED COMPOSITES LETTERS, cilt.15, sa.4, ss.127-137, 2006 (SCI-Expanded)
In this experimental study, which was undertaken to evaluate the combined effects of material direction, thickness and seawater environment on the fatigue behaviour of adhesively bonded and bolted joints widely used in GRP boat building, the specimens, which were produced by composite system, which its matrix material was multi-purpose polyester (Dewester 196 from the Dewilux Inc.) and its reinforcing material was non-crimp, E-glass fibres, has been used. Unjoined control specimens taken from two different panels (thickness of 5 mm and 11 mm) with the direction of 0 degrees, were subjected to the tests carried out under both atmospheric and marine conditions, together with unjoined with the directions of 45 degrees and 90 degrees, bonded and bolted specimens taken from the same panels. The study was started with static tensile tests of unjoined and jointed specimens, which have two different thickness, 5 mm and 11 mm and have been aged in 3.5% of NaCl solution, which represents seawater environment, and the results obtained give suggestions on tensile values, which would be used in tension-tension fatigue tests. The cycling in tension-tension fatigue tests was between tensile maximum and zero stress value and the frequency value applied was 7.5 Hz. The specimens, which were subjected to tests in synthetic seawater environment, had been aged previously. The results occurred depending on the material direction, the thickness and the joining type of the material are given in conclusion by comparison. It was seen that the results obtained by testing the material in synthetic seawater is much lower than the results of obtained from testing similar specimens under atmospheric conditions. However, the cyclic stress curves indicate the same slope, suggesting that the fatigue failure mechanism of both testing conditions is the same and the fibre-related factors dominate.