Steel girder bridge cost optimization using AASHTO specifications

The optimum design of a steel girder is very complex due to the interdependence of the constraints involved, An interactive computer program has been developed which combines the best attributes of conventional design and structural optimization to create a practical tool for structural design of girder bridges. The objective function used in the optimization process is formulated to optimize the total cost of the structure rather than the structure weight. An important feature of the developed methodology is the formulation of the standard analysis member from fabricated component Inputs. Fabricated components are detailed parts that represent each component of the structure exactly as it would be manufactured. Fabricated component tiara is used in the analysis/synthesis process and the design methodology allows consideration of nonprismatic members, The program also allows the design to be performed using either ASD, LFD, or LRFD design methodologies.