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| Cognard, J. Y.; Sohier, L.; Davies, Peter. |
| Composite materials are a key element in weight reduction strategies, so the analysis of the mechanical behavior of assemblies of composite modules is of great importance. Failure initiation in bonded assemblies involving composites is often associated with crack initiation in the adhesive or delamination of the composite plies close to the adhesive joint, caused by interlaminar or through-thickness stresses. Thus, the analysis of the behavior of composites and their assemblies under out-of-plane loadings is necessary in order to optimize such structures. However, few experimental devices are proposed in the literature and they often require thick composite specimens which are not representative of most industrial applications. This paper describes the use... |
| Tipo: Text |
Palavras-chave: Laminates; Adhesion; Stress concentrations; Mechanical testing. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00026/13740/11039.pdf |
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| Tual, Nicolas; Carrere, N.; Davies, Peter; Bonnemains, T.; Lolive, E.. |
| In recent years, many tidal turbine projects have been developed using composites blades. Tidal turbine blades are subject to ocean forces and sea water aggressions, and the reliability of these components is crucial to the profitability of ocean energy recovery systems. The majority of tidal turbine developers have preferred carbon/epoxy blades, so there is a need to understand how prolonged immersion in the ocean affects these composites. In this study the long term behaviour of different carbon/epoxy composites has been studied using accelerated ageing tests. A significant reduction of composite strengths has been observed after saturation of water in the material. For longer immersions only small further changes in these properties occur. No... |
| Tipo: Text |
Palavras-chave: Carbon; Seawater ageing; Diffusion; Mechanical testing. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00278/38964/37504.pdf |
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| Baral, N.; Cartie, D. D. R.; Partridge, I. K.; Baley, C.; Davies, Peter. |
| This paper presents results from a test developed to simulate the water impact (slamming) loading of sandwich boat structures. A weighted elastomer ball is dropped from increasing heights onto rigidly supported panels until damage is detected. Results from this test indicate that honeycomb core sandwich panels, the most widely used material for racing yacht hulls, start to damage due to core crushing at impact energies around 550 J. Sandwich panels of the same areal weight and with the same carbon/epoxy facings but using a novel foam core reinforced in the thickness direction with pultruded carbon fibre pins, do not show signs of damage until above 1200 J impact energy. This suggests that these will offer significantly improved resistance to wave impact.... |
| Tipo: Text |
Palavras-chave: Honeycomb; Three-dimensional reinforcement; Impact behaviour; Mechanical testing. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11311/7840.pdf |
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| Lan, Marine; Cartie, Denis; Davies, Peter; Baley, Christophe. |
| This paper presents results from an experimental study of the influence of embedded defects created during automated fiber tape placement, on the mechanical properties of carbon/epoxy composites. Two stacking sequences have been examined, [(-45°/+45°)3/-45°] and [90°4/0°3/90°4], in which gaps and overlaps have been introduced during fiber placement. These materials have been cured in an autoclave either with or without a caul plate, then analyzed by ultrasonic C-scan. The microstructures were characterized by scanning electron microscopy. In-plane shear tests were performed on the ±45° laminates and showed that the use of a caul plate does not affect mechanical behavior of plies in the embedded defect region. Compression tests were performed on 0/90°... |
| Tipo: Text |
Palavras-chave: Structural composites; Defects; Mechanical properties; Mechanical testing. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00302/41337/40523.pdf |
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| Maurin, Romain; Perrot, Yves; Bourmaud, Alain; Davies, Peter; Baley, Christophe. |
| Polyester resins are widely employed for pleasure boat construction. In order to satisfy new environmental legislation on styrene emissions resin suppliers have proposed modified formulations, but these show lower failure strains under tensile loading. This paper examines the influence of wet ageing on mechanical properties of low styrene polyester, together with standard polyester and vinyl ester resins, and their glass reinforced composites. Results are presented from accelerated ageing in natural sea water for nine months, at temperatures of 20, 40 and 60 degrees C. Nano-indentation was used to study local changes in the resin after ageing. The diffusion kinetics of the low styrene emission resins and their composites are similar to those for standard... |
| Tipo: Text |
Palavras-chave: Polymer matrix composites (PMCs); Environmental degradation; Mechanical testing. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11104/7856.pdf |
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