Mechanical behavior of transparent fiber reinforced polyester composites at extreme temperatures

Abstract

Selecting materials for harsh or extreme environmental conditions can be a challenge. The combination of a harsh environment, large forces over extended periods and the need for lowest possible cost restricts the choice of materials. One potential material is glass fiber reinforced polymers that are widely used in structural systems as load bearing elements, they are relatively low cost and can be tailored to achieve a range of mechanical properties. This investigation presents the preparation of transparent glass fiber reinforced unsaturated polyester composite and the evaluation of its optical and mechanical properties under extreme conditions of temperature. The polyester resin was reinforced with E-glass fibers to manufacture a composite using the hand layup method. Transparency was achieved by modifying the refractive index of the polyester resin to match that of the glass fibers. This investigation also presents the evaluation of glass fiber reinforced unsaturated polyester under quasi-static tension loading and puncture testing using a drop weight at extreme conditions. The results showed that the reinforced composite had a higher fracture stress and chord modulus at all temperatures ranging from +60 [degree]C to -80 [degree]C as compared to the unreinforced polyester matrix. The unreinforced polyester has a higher stiffness at lower temperatures due to reduced polymer chain mobility and higher clamping pressure of the matrix on the glass fiber reinforcement. The damage created by the impact reduces with decreasing temperatures, while the energy absorb remains constant with temperature.