摘要: |
This report paper summarizes progress on a research program to investigate the use of composite materials for overhead sign bridges, as well as the assembly of these structures without fasteners. A composite overhead sign bridge was designed and analyzed. The traditional profile shapes, which are in use for steel sign bridges, were not copied in composite materials. Instead two types lineals with a special rectangular cross sections for functionality were designed. The crosssectional shape and fiber architecture of these tubes is dominated by the requirement for a snap-fit assembly. The complexities in geometry and fiber architecture can easily be handled by an automated Pultrusion process. Since Pultrusion-dies are expensive the lineals were first manufactured by hand lay-up, and resin infusion on wood tooling. The snap-fit joint created by both parts was subsequently assembled and tested in order to provide a proof of concept without expensive Pultrusion-dies or the added cost of die modifications. As a next step the most extensively loaded joint area in the sign bridge structure was assembled from the two Pultruded tubular sections and subject to the loads which were derived from the analysis. As such the load factors and failure modes have been established. This report outlines a research program undertaken at CSSI to investigate the feasibility of a sign structure which can be erected quickly. The feasibility of a fastenerless 90-ft sign truss in composite materials has been investigated. / NOTE: Final rpt. / Supplementary Notes: Sponsored by California State Dept. Transportation, Sacramento. Div. of Research and Innovation. / Availability Note: Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5301 Shawnee Road, Alexandria, VA, 22312, USA. |