Fiberglass-reinforced plastic properties: buyer reference

Pultruded profiles concentrate continuous fibers in the production direction, so longitudinal properties are much higher than transverse properties. Molded grating, filament-wound pipe, chopped-fiber SMC and quasi-isotropic laminates distribute reinforcement differently and need different design data.

Thickness and full-section behavior also matter. A thin coupon may not represent a thick profile, a joint, a hollow section or a surface-rich laminate. Ask the supplier to identify whether data comes from production coupons, witness panels, full sections or qualification specimens.

Record the standard edition, specimen geometry, fiber direction, conditioning, test temperature, sample count and statistic. Strength reported as an average is not equivalent to a minimum or a characteristic value. ASTM D7290 describes a statistical route for characteristic values used in civil engineering composite applications.

Temperature, moisture, chemicals, UV exposure, sustained load and fatigue can require reduction factors. The supplier should state which reductions are already included and which remain the engineer's responsibility.

Request only properties tied to the real failure modes. A grating RFQ needs panel load/deflection, bar properties, cross-bar integrity, slip and fire evidence. A structural profile RFQ needs directional coupon values, full-section stiffness, connections and environmental reductions. Pipe needs pressure/stiffness basis, liner and joint data.