EVALUATION OF PULTRUDED FRP COMPOSITES FOR STRUCTURAL APPLICATIONS

Fiber reinforced plastic (FRP) composites (E-glass, carbon fiber, poly ester, and epoxy matrix) were fabricated using ''pultrusion,'' a cost- effective process for manufacturing fiber/matrix composites. Investiga tion of the design principles governing civil structures prove that st iffness (elastic modulus)/density rather than strength/density is the most critical property of these materials. Among other variables, larg e fiber-volume fraction, low void ratio, and fiber straightness are es sential for high modulus. The feasibility of rapidly measuring the ela stic modulus of pultruded composites during the manufacturing process using acoustic wave velocity was therefore explored. Results were comp ared with conventional flexure tests and resonant frequency tests. Dam ping was also comparable to that of steel. Comparison with conventiona l structural materials reveal that composites currently available in t he market are competitive structural materials only if secondary consi derations govern the design.