Reliability-Based Optimization of Fiber-Reinforced Polymer Composite Bridge Deck Panels

A reliability-based optimization procedure is developed and applied to minimize the weight of eight fiber-reinforced polymer composite bridge deck panel configurations. The method utilizes interlinked finite element, optimization, and reliability analysis procedures to solve the weight minimization problem with a deterministic strength constraint and two probabilistic deflection constraints. Panels are composed of an upper face plate, lower face plate, and a grid of interior stiffeners. Different panel depths and stiffener layouts are considered. Sensitivity analyses are conducted to identify significant design and random variables. Optimization design variables are panel component ply thicknesses, while random variables include load and material resistance parameters. It was found that panels were deflection governed, with the optimization algorithm yielding little improvement for shallow panels, but significant weight savings for deeper panels. The best design resulted in deep panels with close stiffener spacing to minimize local upper face plate deformations under the imposed traffic (wheel) loads.