Optimum design of a reinforced plastic bridge girder

This paper describes the results of an analytical and experimental investigation concerned with the optimum design of a fiberglass-reinforced plastic flexural number. In the initial phase of the study, seven members were designed, fabricated, load-tested and subsequently analyzed. Design modifications were made in each subsequent specimen based on results from the experimental and analytical study. The initial configurations were selected on the basis of intuitive arguments and empirical optimum design concepts. In order to achieve a more efficient and economical structural system, an iterative algorithm for optimum geometric configuration was developed and used in conjunction with an optimality criterion for optimum member sizing. This procedure was applied to the design of five separate flexural members and final design data for these members are presented and discussed.