Finite Element Modeling Approach and Performance Evaluation of Fiber Reinforced Polymer Sandwich Bridge Panels

摘要

In the United States, about 27% of the bridges are classified as structurally deficient or functionally obsolete. Bridge owners are continually investigating methods to effectively retrofit existing bridges, or to economically replace them with new ones. Modern composite materials for structural applications, at one time only in the domain of aerospace engineering, are increasingly making their way into civil engineering applications. In addition to retrofitting current concrete and steel structures using FRP sheets or plates, a great deal of work is being conducted to develop versatile, fully-composite structural bridge systems. To reduce the self-weight and also achieve the necessary stiffness, sandwich panels are usually used for bridge decks. However, due to the geometric complexity of the FRP sandwich, convenient methods for bridge design have not been developed. The present study aims at developing finite element modeling techniques for sandwich structures. Parametric studies are carried out with the objective of developing equivalent elastic properties, which would be useful parameters in design. A distinction is made between in-plane and out-of-plane behavior, and properties are derived accordingly. The performance of the sandwich, such as the interface stress between the flange and wearing surface can be evaluated. Therefore, through finite element modeling, optimization can be achieved in order to minimize the interface stress. The contribution of stiffness of the wearing surface to structural performance, a factor which is not usually accounted for in typical design procedures, is also examined. An effort is also made to analyze the temperature effects on the structures performance. A conceptual approach aimed at studying the thermal performance of the panel due to both uniform and gradient temperature variations is presented.