Temperature-sensitive mechanical properties of GFRP composites in longitudinal and transverse directions: A comparative study

A comparative study was conducted to evaluate the temperature-sensitive mechanical properties of glass fibre reinforced polymer (GFRP) composites in the longitudinal and transverse directions. GFRP coupons with different shear span-to-depth ratios were tested under three-point static bending test at temperatures ranging from room temperature up to 200 °C. Timoshenko Beam Theory-based procedure was then adopted to calculate the flexural and shear moduli of the GFRP laminates under moderate and elevated in-service temperatures. The results showed that the mechanical properties of the transversely cut specimens is affected more by the increase in temperature than the longitudinally cut specimens. Similarly, the interlaminar shear and flexural strengths of GFRP composites were found influenced more by elevated temperature compared to the stiffness properties. Moreover, the shear modulus undergone more severe degradation compared to the flexural modulus. Simplified empirical models were proposed to estimate the mechanical properties of the GFRP pultruded laminates in both the longitudinal and transverse directions at varying temperatures.