Trans RINA, Vol 152, Part B2, Intl J Small Craft Tech, 2010 Jul-Dec 6. CONCLUSIONS


Three layups of L-bend composite specimens were tested under displacement control up to 100mm displacement. The failures of the specimens were monitored using acoustic emission. Failure prediction around the bend was performed using nonlinear finite element analysis. Load carrying capacity, failure initiation and progression were studied for each laminate. The bending load in this study generated more of interlaminar tensile compared to interlaminar shear stress.


stress 8.


Performance of Layup 3 was greater than the other two layups. The secondary reserve strength of layup 3 post initial failure (due to the presence of Unidirectional fibres), helped in carrying more load up to 1800N. Load carrying capacity of Layup 1 was greater than layup 1 but suffered catastrophic brittle failure. Layup 2 & 3 had DB layers which hold the structure in place, also helped in avoiding the catastrophic failure as seen with layup 1.


The damage mechanism, failure initiation & progression were assessed using Acoustic Emission parameters. Considering that the fibre composite systems used are fibre mats, and the specimens were subjected to an out- of-plane bending load, the proposed failure mechanisms are reasonable. The residual strength of the structure was identified so as to assist the boat builders in designing the curved structures. The improved knowledge of the low ratio of delamination strength to ultimate tensile strength for the laminates tested (particularly the mixed laminates - Layup 2 and Layup 3)


designers. 7.


ACKNOWLEDGEMENTS 14.


First presented at the Pacific 2010 International Maritime Conference, January - 2010, Sydney, Australia.


15.


8. 1.


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©2010: The Royal Institution of Naval Architects


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