Evaluation of Pultruded FRP Composites for Structural Applications

Abstract

Fiber reinforced plastic (FRP) composites (E-glass, carbon fiber, polyester, and epoxy matrix) were fabricated using “pultrusion,” a cost-effective process for manufacturing fiber/matrix composites. Investigation of the design principles governing civil structures prove that stiffness (elastic modulus)/density rather than strength/density is the most critical property of these materials. Among other variables, large fiber-volume fraction, low void ratio, and fiber straightness are essential for high modulus. The feasibility of rapidly measuring the elastic modulus of pultruded composites during the manufacturing process using acoustic wave velocity was therefore explored. Results were compared with conventional flexure tests and resonant frequency tests. Damping was also comparable to that of steel. Comparison with conventional structural materials reveal that composites currently available in the market are competitive structural materials only if secondary considerations govern the design.