Incorporation of corrosion effects in reliability-based optimization of composite hybrid plate girders

Available data suggest that corrosion may have significant effects on the reliability of structural components and systems including highway bridges, offshore platforms, and hydraulic structures. Therefore, reliability-based design and/or optimization of a structure or component placed during its intended service life in a corrosive environment must take the effects of this environment into account. A reliability-based optimization approach to the design of composite hybrid plate girders under corrosion effects is developed herein. The proposed approach incorporates all constraints specified in the AASHTO bridge code considering time-dependent corrosion effects. Numerical examples illustrate the application of the proposed approach to time-dependent reliability-based optimum design of both unstiffened and stiffened composite hybrid plate girders for highway bridges.