Due to their high fatigue life, specific strength and specific stiffness in comparison with steel, carbon-fibre reinforced polymer (CFRP) cables have attracted the infrastructure industry interest in recent years, primarily for use as structural tendons. Particularly the oil and gas industry showed interest for application in offshore platform anchorage systems, because of their exceptional corrosion and creep/relaxation behaviour. In such applications, the cables need to be tensioned in service and to be bent around relatively small-diameter spools for transportation and maintenance. Therefore, their tensile and bending behaviour is a subject of great concern. The aim of this work was to perform a test program on 1 × 19 CFRP cables in two different situations: tensile loading and four-point bending loading. Finite element models were developed to simulate both conditions, including frictional contact between the cable wires. A simplified analytical model was also used to predict the cable behaviour in tension. Numerical predictions were compared to experimental data showing relatively good accuracy, unlike the verified analytical model. CFRP cables presented outstanding tensile behaviour, but bending over small radius spools could not reach the performance of steel wire ropes. Furthermore, simulation could only fairly predict bending below strains of μ1,000 μe for the external rods, beyond which the cable presented highly non-linear behaviour that could not be simulated by the numerical model.

Carbon Fiber Reinforced Polymer (CFRP) cables, due to their outstanding performance in terms of specific stiffness and strength, are usually found in civil construction applications and, more recently, in the Oil & Gas sector. However, experimental data and theoretical solutions for these cables are very limited. On the contrary, several theoretical and numerical approaches are available for isotropic cables (metallic wire ropes), some of them with severe simplifications, nonetheless showing good agreement with experimental data. In this study, experimental tensile results for 1×7 CRFP cables were compared to a simplified analytical model (assumed transversally isotropic) and to a 3D finite element model incorporating the experimental uncertainty in important input parameters: longitudinal elastic modulus, Poisson's ratio, static friction coefficient and ultimate tensile strain. The average experimental breaking load of the cable was 190.25 kN (coefficient of variation of 1.74%) and the agreement with the numerical model predictions were good, with an average-value deviation of -1.15%, which is lower than the experimental variations. The simplified analytical model yielded a discrepancy above 10%, indicating that it needs further refinement although much less time consuming than the numerical model. These conclusions were corroborated by statistical analyses (i.e. Kruskal-Wallis and Mann-Whitney). KeywordsComposite cables, finite element analysis, analytical model, design of experiments, uncertainty quantification.

Resin Transfer Moulding (RTM) as it is most known process in the Resin Injections family, is an extensively studied and used processing method. This process is used to manufacture advanced composite materials made of fibres embedded in a thermoset polymer matrix. Fibre reinforcement in RTM processing of polymer composites is considered as a fibrous porous medium regarding its infiltration by the polymer resin. In this sense, the present work aims the computational analysis of a fluid in a porous media for a RTM composite moulding by using the ANSYS CFX® commercial software. In order to validate the numerical study of the fluid flow in a known RTM system, experiments was carried out in laboratory to characterize the fluid (vegetal oil) flowing into the porous media (0/90 glass fibre woven), were pressure and fibre volume fraction have been fixed. The numerical simulation provides information about volume fraction, pressure and velocity distribution of the phases (resin and air) inside the porous media. The predicted results were compared with the experimental data and its has shown a solid relationship between them.

In the processing of high performance composite materials, the RTM process has been widely used by many sectors of the industry. This process consists in injecting a polymeric resin through a fibrous reinforcement arranged within a mold. In this sense, this study aims to simulate the rectilinear infiltration of pure resin and filled resin (40% CaCO3) in a mold with glass fiber preform, using the PAM-RTM commercial software. Numerical results of the filling time and fluid front flow position over time were assessed by comparison with the experimental data and a good accuracy was obtained.

Composite material can be defined as a combination of two or more materials on a macroscale to form a useful material, often showing properties that none of the individual independent components shows. Resin Transfer Molding (RTM) is one of the most widely known composite manufacturing technique of the liquid molding family, being extensively studied and used to obtain advanced composite materials comprised of fibers embedded in a thermoset polymer matrix. This technique consists in injecting a resin pre-catalysed thermosetting in a closed mold containing a dry fiber preform, where the resin is impregnated. The aim of this study is to investigate the effect caused by the use of CaCO3filled resin on the characteristics of the RTM process. Several experiments were conducted using glass fiber mat and polyester resin molded in a RTM system with cavity dimensions of 320 x 150 x 3.6 mm, at room temperature, and different CaCO3content (0, 10, 20, 30 and 40% in weight). The results show that the use of filled resin with CaCO3influences the resin viscosity and the porous media permeability, making it difficult to fill the porous media during the molding process, however it is possible to make composite with a good quality and low cost.

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The tensile behavior of cables and wire ropes has been widely explored in the literature, with many analytical, numerical and experimental results available. However, their bending behavior is still not yet fully comprehended, especially when dealing with cables made of non-isotropic materials. When these materials are bended over small diameter sheaves or drums, they may experience large strains, causing nonlinearities that are not captured by any known analytical model. The aim of the present work is to numerically verify through finite-element method the tensile and bending behavior of composite CFRP cables. The numerical results were compared with experimental data. Good correlation between them was found in a four-point bending test configuration, even at large displacements and with a nonlinear response. Hybrid cable constructions (using aramid and glass rods) were also numerically analyzed relative to their tensile and bending behavior, achieving satisfactory results.

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