Structural Optimization of FRP Web Core Decks

Abstract

The writers report an efficient technique for the analysis and design of fiber-reinforced polymer (FRP) web core decks for highway culverts. This technique is based on finite-element modeling and an iterative optimization scheme for different spans, ranging from 2–5 m, that have a carriageway width of 7.5 m, in accordance with Indian loading conditions. The FRP web core deck system that is considered in this paper consists of laminated web cores with equally spaced webs, oriented only in the transverse direction, and were placed between the top and bottom laminated face plates. The culvert decks were simply supported on two opposing edges, whereas the remaining edges were assumed to be free. These were subjected to self-weight and imposed live load. The thicknesses of the webs, top and bottom face plates, number of webs in the core, and depths of the web core of the FRP culverts are considered as the basic design parameters for the structural optimization. The optimization followed different criteria based on the deflection limit, global buckling, the Tsai-Hill failure model, and the Tsai-Wu failure model. The writers used computer software for parametric modeling with modified scripts. The design parameters were varied to obtain different trial solutions in a two-stage optimization process. The optimum dimensions were finalized based on the solutions that corresponded with the minimum volume of the FRP material.