Influence of the properties of an orthotropic GFRP deck on the dynamic response of a hybrid road bridge

Abstract

The use of multicellular Glass Fiber Reinforced Polymer (GFRP) deck panels in the rehabilitation and construction of bridges has increased over the last 30 years due to several benefits, such as: low maintenance cost, fast installation, corrosion resistance, and high strength-to-weight ratio. Due to the orthotropic nature of GFRP decks and their complex cross-section geometry, expensive computational problems may be obtained when bridges that include these elements are analyzed under traffic loads. Therefore, this paper studies the dynamic response of a GFRP-steel road bridge modelling the multicellular GFRP deck as an orthotropic plate. For this purpose, a finite element model of the hybrid structure is developed, and a sensitivity analysis is carried out to investigate the influence of the mechanical properties of the orthotropic element on the bridge behavior. The roughness of the pavement, the degree of composite action between the deck and the stringers, the multibody dynamic model of a truck, and the vehicle-bridge interaction phenomenon are included in the analyses. Results indicate that the most relevant properties of the orthotropic plate on the response of the structure are the modulus of elasticity in the longitudinal direction, the modulus of elasticity in the transverse direction, and the shear modulus. Also, achieving a full composite action and avoiding deterioration of road are identified as key aspects to reduce the vibration levels on the hybrid bridge.