Mechanical behaviour of pultruded glass fibre reinforced polymer composites at elevated temperature: Experiments and model assessment

Abstract

This paper presents an experimental and analytical study about the mechanical response at elevated temperature of glass fibre reinforced polymer (GFRP) pultruded profiles. The paper first describes results of DMA and DSC tests that were used to evaluate the glass transition and decomposition processes of the GFRP pultruded material. The paper then describes an extensive study about the tensile, shear and compressive responses of the GFRP material at temperatures varying from 20°C to 250°C. In these tests the mechanical responses of the GFRP material as a function of temperature were assessed, namely the load–deflection curves, the stiffness, the failure modes and the ultimate strength. Results obtained in these experiments confirmed that the mechanical performance of GFRP is severely deteriorated at moderately high temperatures, particularly when loaded in shear and compression, owing to the glass transition of the resin. The final part of this paper assesses the accuracy of different empirical models and one phenomenological model to estimate the tensile, shear and compressive strengths of GFRP pultruded material as a function of temperature. All empirical models, including a function based on Gompertz statistical distribution suggested in the present paper, provided accurate estimates of tensile, shear and compressive strengths as a function of temperature. The phenomenological model was less accurate and in general provided non conservative estimates of material strength.