Numerical Analysis Of Static And Dynamic Response Of FRP Sandwich Deck Bridges

Fiber reinforced polymer (FRP) is a new structural material which is gaining popularity in the bridge community in recent years. It has shown superior properties such as high strength-to-weight ratio and corrosion resistance, etc. The FRP sandwich hollow panel is one of the FRP systems and has been proposed for applications in bridge construction with a good prospect. It can be applied for old bridge repair and replacement of damaged decks, and it can also be used in new bridge deck systems. Because the FRP bridge deck is a new structural component, there is a growing need to understand the behavior of FRP deck bridges such as the static and the dynamic response of bridges with a FRP deck.The load distribution throughout the bridge deck and the vehicle-induced impact on bridges are of primary importance in the design of bridges. The loads distribution factor and the dynamic impact factor have been used world wide in bridge design, and extensive research (including experimental and theoretical) has been conducted to determine these factors for bridges with conventional decks. The characteristics of the FRP decks (such as mass, stiffness and damping) are significantly different from those of the traditional concrete and steel decks, which could result in different performance of FRP deck bridges from the traditional bridges. However, the distinctive performance of bridges with FRP decks has rarely been studied. For this reason, some detailed numerical analyses are used in the present study to investigate the load distribution and the dynamic response of FRP deck bridges.Due to the geometrical complexity of the FRP sandwich panel configuration, finite element modeling and analysis for an entire bridge can be very complicated, if not impossible. The present study reduces FRP sinusoidal core sandwich panel to a solid orthotropic plate using the equivalent properties derived, the results obtained from the analysis with the simplified model were compared with those from the tests and a good correlation was achieved, so it was verified to be an effective method in investigating the performance of entire bridges with FRP deck; Using the equivalent model, at first the present study analyzed a steel girder bridge after the original deck was replaced with a FRP deck in Kansas. The load distributions obtained from the analysis were compared with those from the field tests and a good correlation was achieved. And then, some detailed finite element analyses were used to further investigate the load distribution of FRP bridge deck systems, a steel multi-girder bridge and a concrete multi-girder bridge were studied. By integrating the bridge and vehicle systems into a bridge-vehicle coupled system based on deformation compatibility, the present study using the developed MATLAB software this paper studied the dynamic performance of bridges with FRP decks, and investigated the dynamic response of a simple support slab FRP bridge, a steel multi-girder bridge with FRP deck, and a prestressed concrete multi-girder bridge with FRP deck. The dynamic response of bridges caused by a 3-axle truck was obtained considering the influence of road roughness as well as vehicle velocity. For both the static analyses and the dynamic analyses of FRP girder bridges, the author considered two composite actions which were FRP deck partially composite or FRP deck fully composite between the deck and girders. The performance of bridges was compared between the FRP and the corresponding concrete deck bridges, and some valuable research conclusions were obtained. This study provides some helpful rationale for the better application of FRP deck in the bridge community.