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This article studies the hygrothermal behavior of E-glass fiber-reinforced polyester composites containing filler additives. Three different cases of a material exposed to water are investigated at two various temperatures: 45℃ and 65℃. First, both lateral sides are exposed to water at the same temperature (symmetric absorption). Second, one side is exposed to water at a certain temperature and the other side is exposed to ambient air (dissymmetric absorption I). Third, both lateral sides are exposed to water at varied temperatures (dissymmetric absorption II). The kinetics of water absorption follows the Fick’s second law. The water concentration is higher on the surface of the material and it decreases continuously toward the core of the model. The increase in the temperature and the higher level of additives raise the absorbed moisture and the diffusion coefficient. The software “Abaqus” is used to simulate the water diffusion through the material. The comparison between the experimental and numerical results shows that the model can predict the hygrothermal behavior of the polyester/glass fiber in symmetric and dissymmetric absorption.

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This is a statistical study of the dynamic humidity diffusion through the polyester/glass fibre composite. It analyses the influence of the environmental conditions like the temperature, the flow velocity and the pressure on the humidity diffusion through the composite material. It is divided into an experimental plan and a data analysis, which exploit the experimental results in order to analyse the process of humidity diffusion by highlighting the effects of the influencing parameters. The increase in the temperature, the pressure, the flow velocity and the percentage of fillers additives (ASP400) induce an augmentation in the diffusion coefficient and the amount of absorbed humidity. We can affirm that the flow velocity and the pressure have a higher impact on the diffusion parameters than the temperature. Moreover, the increase in the percentage of the fillers additives (ASP400) decreases the effect of the pressure and the flow velocity on the diffusion parameters.

The hygrothermal behavior of the polyester/glass fiber composite is studied under the effect of the pressure in sea water. Fillers additives Aluminum Silicate Pigments are inserted to the composite material. Humidity absorption is made through one lateral side, under different temperature. The humidity concentration is higher on the surface and it continuously decreases toward the core of the material. At high temperature, the humidity absorption curve falls. It is caused by the coalescence of cracks propagating through the composite material, which are created by the stress concentration at a point of the free volume existing in the material. The rise of the percentage of the fillers additives and the pressure induces an augmentation of the diffusion coefficient and the amount of absorbed humidity. The finite element method is utilized to present a numerical model of the humidity absorption process. The comparison between numerical and experimental results confirms that the hygrithermal behavior of the polyester/ glass fiber composite could be numericallypredicted.