SBIR-STTR Award

Composite materials offer several advantages over metals for portable bridging: weight savings of 25% or more, corrosion and fatigue resistance. The design of a composite structure is complex: composite properties are highly anisotropic, moisture absorption and temperature changes cause considerable strains and fit-up sensitivity is high. U.s. composites will design a composite multi-hollow bridge deck based on new manufacturing techniques including braiding and wet lamination to achieve the necessary performance at an acceptable cost. Cds microcomputer codes will be used to quickly converge on a preliminary design, then a final design will be verified by finite element analyses. The designers will apply their experience from large, dynamically loaded composite rotors to ensure adequacy of the entire structure: composites, metal attachments and composite/metal joints

U.S. Composites designed a composite bridge deck to replace an aluminum deck in the tri-arch portable bridge. A unique combination of computer controlled wet braiding and resin transfer molding is planned for fabrication of the multi-hollow deck. The design includes a contact stress isolation layer to protect the deck from abrasion and concentrated loads under vehicle tires and treads. A partial span segment of the deck will be fabricated and tested to determine fiber volume fraction, void content, compression strength, compression after 1500 in. Lb per inch impact, and contact stress testing. A full span deck may be fabricated to verify the manufacturing technique and allow testing of a complete unit