Fatigue response of fabric reinforced polymeric composites

Abstract

Fiber Reinforced Polymeric (FRP) Bridge decks have been an active area of research for the past 10 yrs. In order to better understand the long term efficiency and reliability of FRP bridge decks, and to develop design and test specifications, laboratory testing and characterization of the deck systems and the FRP material, is necessary. Majority of the FRP deck systems available to date are made of glass-reinforcing fibers in the form of fabrics, mats, rovings, etc. Currently, the fatigue response of multidirectional composite is not readily available in the literature and much work needs to be done to understand the behavior of these composites under fatigue loading.;In this study three fabric based glass FRP composites used in bridge components were tested under fatigue loading. A fatigue life prediction model is proposed, with internal strain energy as damage metric, to predict the useful life of FRP composites based on the experimental results. The experimental and predicted lives at various strain levels were compared (S-N curves) and the model was found to be conservative within 10% error.;Two lightweight Glass FRP composite modular bridge decks were evaluated for structural integrity and degradation in bending rigidity under repetitive simulated wheel load (HS20-44 design truck load) to determine the applicability of the decks to bridge applications. The first deck failed due to local punching shear failure after 230,000 cycles. The second deck was reinforced in the loading area with 100 oz/yd2 of fiber in the transverse direction. No damage was observed for two million cycles and there was no considerable degradation in bending rigidity.