The Experts below are selected from a list of 16650 Experts worldwide ranked by ideXlab platform
Frans S.k. Bijlaard - One of the best experts on this subject based on the ideXlab platform.
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effects of hygrothermal aging on glass fibre reinforced polymer laminates and adhesive of frp composite bridge Moisture Diffusion characteristics
Composites Part A-applied Science and Manufacturing, 2014Co-Authors: Xu Jiang, Henk Kolstein, Frans S.k. Bijlaard, Xuhong QiangAbstract:Abstract Moisture absorption and hygrothermal aging in glass-fibre-reinforced polymer laminates and a structural adhesive of FRP composite bridge are studied. By gravimetric experiments, the Moisture Diffusion in GFRP laminates and adhesive is characterised in four environmental aging conditions (20 °C–50% RH (relative humidity), 20 °C–water, 40 °C–96% RH and 40 °C–water). Based on the analytical models from 1D and 3D Moisture Diffusion theories, the Moisture Diffusion coefficients are determined by the best least-square curve fitting to experimental data. Finite Element models are further developed, which subsequently validate the analytically obtained Moisture Diffusion coefficients. The FE analysis indicates that, for identification of 3D Moisture Diffusion coefficients of anisotropic FRP materials, the equivalent Diffusion coefficient method is unreliable, and the 3D Moisture Diffusion theory is essential. Furthermore, mass loss is found for the Square and Rectangular specimens under 40 °C–water condition. Polymer relaxation is observed for structural adhesive.
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Moisture Diffusion and hygrothermal aging in pultruded fibre reinforced polymer composites of bridge decks
Materials & Design, 2012Co-Authors: Xu Jiang, Henk Kolstein, Frans S.k. BijlaardAbstract:Abstract Gravimetric experimental studies were undertaken to characterise the Moisture Diffusion process in pultruded Fibre Reinforced Polymer (FRP) composites of bridge decks exposed to the vapour environmental aging condition as well as water immersed condition at temperatures of 20 °C and 40 °C respectively. After a short-term (250 days) aging duration, the Moisture weight gain curves as a function of time were obtained. Comparing with the vapour conditions, FRP composites immersed in water resulted in much higher Moisture uptake levels, around 3% of the initial self-weight. Based on the one-dimensional Moisture Diffusion theory, the Moisture Diffusion coefficients of FRP composites under different aging conditions were identified by the best least-square curve fitting to the experimental data. The obtained results indicated that high temperature can speed up the Moisture Diffusion rate, and the Moisture equilibrium contents were mainly governed by the humidity of aging environment. Large portion of polymer relaxation was evident from the experimental data in the aging condition of 20 °C-water and 40 °C-water. Moisture desorption tests confirmed that, for the aging conditions of 40 °C-96% relative humidity (RH) and 40 °C-water, mass loss of FRP composites took place. No significant variations on Moisture Diffusion characteristic of FRP specimens from different parts of the bridge deck element can be drawn expect that, flange part specimens absorbed less Moisture content than the two web parts.
Baolin Wan - One of the best experts on this subject based on the ideXlab platform.
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Modeling of Moisture Diffusion in FRP Strengthened Concrete Specimens
Journal of Composites for Construction, 2008Co-Authors: Zhenyu Ouyang, Baolin WanAbstract:Modeling the movement and distribution of Moisture in the fiber-reinforced polymer (FRP) composites strengthened concrete structure is important because the interfacial adhesion between FRP and concrete is susceptible to Moisture attack. Using relative humidity as the global variable, the Moisture Diffusion governing equation was derived for the multilayered system in this study. The Moisture diffusivity (Diffusion coefficient) and the isotherm curve, which correlates the Moisture content to environmental relative humidity, of each constitutive material (concrete, epoxy, and FRP) were experimentally determined. A multilinear diffusivity model was developed for concrete based on desorption test, and a linear diffusivity model was proposed for epoxy adhesive based on absorption test. A simple method was developed to directly measure the FRP/concrete interface region relative humidity (IRRH). Finite-element analysis was performed to study the Moisture Diffusion in the FRP-adhesive-concrete system. The IRRH v...
Xu Jiang - One of the best experts on this subject based on the ideXlab platform.
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effects of hygrothermal aging on glass fibre reinforced polymer laminates and adhesive of frp composite bridge Moisture Diffusion characteristics
Composites Part A-applied Science and Manufacturing, 2014Co-Authors: Xu Jiang, Henk Kolstein, Frans S.k. Bijlaard, Xuhong QiangAbstract:Abstract Moisture absorption and hygrothermal aging in glass-fibre-reinforced polymer laminates and a structural adhesive of FRP composite bridge are studied. By gravimetric experiments, the Moisture Diffusion in GFRP laminates and adhesive is characterised in four environmental aging conditions (20 °C–50% RH (relative humidity), 20 °C–water, 40 °C–96% RH and 40 °C–water). Based on the analytical models from 1D and 3D Moisture Diffusion theories, the Moisture Diffusion coefficients are determined by the best least-square curve fitting to experimental data. Finite Element models are further developed, which subsequently validate the analytically obtained Moisture Diffusion coefficients. The FE analysis indicates that, for identification of 3D Moisture Diffusion coefficients of anisotropic FRP materials, the equivalent Diffusion coefficient method is unreliable, and the 3D Moisture Diffusion theory is essential. Furthermore, mass loss is found for the Square and Rectangular specimens under 40 °C–water condition. Polymer relaxation is observed for structural adhesive.
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Moisture Diffusion and hygrothermal aging in pultruded fibre reinforced polymer composites of bridge decks
Materials & Design, 2012Co-Authors: Xu Jiang, Henk Kolstein, Frans S.k. BijlaardAbstract:Abstract Gravimetric experimental studies were undertaken to characterise the Moisture Diffusion process in pultruded Fibre Reinforced Polymer (FRP) composites of bridge decks exposed to the vapour environmental aging condition as well as water immersed condition at temperatures of 20 °C and 40 °C respectively. After a short-term (250 days) aging duration, the Moisture weight gain curves as a function of time were obtained. Comparing with the vapour conditions, FRP composites immersed in water resulted in much higher Moisture uptake levels, around 3% of the initial self-weight. Based on the one-dimensional Moisture Diffusion theory, the Moisture Diffusion coefficients of FRP composites under different aging conditions were identified by the best least-square curve fitting to the experimental data. The obtained results indicated that high temperature can speed up the Moisture Diffusion rate, and the Moisture equilibrium contents were mainly governed by the humidity of aging environment. Large portion of polymer relaxation was evident from the experimental data in the aging condition of 20 °C-water and 40 °C-water. Moisture desorption tests confirmed that, for the aging conditions of 40 °C-96% relative humidity (RH) and 40 °C-water, mass loss of FRP composites took place. No significant variations on Moisture Diffusion characteristic of FRP specimens from different parts of the bridge deck element can be drawn expect that, flange part specimens absorbed less Moisture content than the two web parts.
Stephen Grove - One of the best experts on this subject based on the ideXlab platform.
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multi scale modelling of Moisture Diffusion coupled with stress distribution in cfrp laminated composites
Composite Structures, 2016Co-Authors: Maozhou Meng, M J Rizvi, Stephen GroveAbstract:Abstract Laminated composite structures operating in a marine environment are subject to Moisture ingress. Due to the slow Diffusion process of Moisture, the distribution of Moisture is not uniform so that the laminates can develop hygrothermal stresses. An accurate prediction of the Moisture concentration and the associated hygrothermal stress is vital to the understanding of the effect of marine environment on failure initiation. The present paper investigates the time-dependent Moisture Diffusion and the stress distribution in carbon fibre reinforced polymeric (CFRP) composites by means of experimental study and Finite Element Analysis (FEA). Samples were made from CFRP pre-preg autoclave-cured, and then immersed in fresh water and sea water at a constant 50 °C for accelerated Moisture Diffusion. Laminates with [0] 16 , [90] 16 , [±45] 4s lay-up sequences were investigated. A multiscale 3D FEA model was developed to evaluate the interfacial stresses between polymer matrix and carbon fibre and the stress distribution in the composite laminates. The analysis revealed that both the stress distribution and stress level are time-dependent due to Moisture Diffusion, and the interphase between fibres and matrix plays an important role in both the process of Moisture Diffusion and the stress/strain transfer. The interlaminar shear stresses of the laminates induced by hygrothermal expansion exhibited a significant specimen edge effect. This is correlated with the experimental observations of the flexural failure of laminates.
P.k. Sinha - One of the best experts on this subject based on the ideXlab platform.
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Moisture Diffusion in variously shaped fibre reinforced composites
Computers & Structures, 1996Co-Authors: P. K. Aditya, P.k. SinhaAbstract:The versatility of composite material lies in its unique characteristics of high strength and stiffness combined with light weight. Like all other materials this is also susceptible to Moisture coupled with temperature. Moisture susceptibility is directly associated with the Diffusion of Moisture through polymeric composites. Moisture Diffusion coefficients of polymer composites are found to depend on a number of factors, such as Moisture concentration and environmental temperature, fibre volume fraction, and the diffusivity of the fibre (if permeable) and polymer matrix. Moisture Diffusion coefficients of polymer composites also depend on the shape of the reinforcing fibre. In the present investigation single fibre composite models reinforced with variously shaped reinforcing fibres are used for the evaluation of the Diffusion coefficients. The finite element analysis approach is developed based on the Galerkin formulation using nine-node isoparametric elements.
