Mechanical properties of pultruded GFRP at intermediate strain rates

Pultruded glass fibre reinforced polymer (GFRP) has been widely used in civil engineering as a high-performance material due to its light weight and durable nature. Knowledge of the mechanical behaviour of pultruded GFRP subjected to dynamic loads is vital for predicting its structural behaviour during earthquake or other vibrational loadings. While the behaviour of pultruded GFRP at both high (e.g. impact) and low (e.g. static) strain rates has been studied previously, this paper investigates the influence of intermediate strain rates on its mechanical properties, including tensile strength, elastic modulus, Poisson's ratio, and in-plane shear modulus. Repetitive tests are conducted under axial tension loading at intermediate strain rates from 2.5 × 10^-3 to 2 s⁻¹. Uniform coupons with three fibre orientations (0°, 20°, and 90°) are used to obtain the properties accordingly. Two constitutive material models are validated based on experimental results to better predict the material response of pultruded GFRP including the strain rate effects. This work contributes knowledge on the material responses of pultruded GFRP at intermediate strain rates which will aid the development of future design guidelines for pultruded GFRP.