DEVELOPMENT OF EFFICIENCY BASED STANDARDS FOR OPTIMUM DESIGN OF STIFFENED PLATE GIRDERS

In recent years, stiffened plate girders have been used extensively for long spans due to its high flexural rigidity and buckling resistance. While designing, the amount of costly steel used in a girder can be reduced by adopting optimum dimensions for web depth, web thickness, flange thickness, flange breadth and spacing of stiffeners. Such design can finally result in an economical design. Indian standards have code provisions which can be used for design of stiffened plate girders. However, relatively little attention has been devoted to developing efficiency based standards in the design of plate girders. These efficiency based standards in the form of design charts can help a designer in the economical design of stiffened plate girders considering strength and serviceability conditions. Herein, relationships between the design variables are developed using genetic algorithm (GA) based optimization formulation. Both transversely stiffened and corrugated web plate girders are considered. The relationships are further used to develop design charts which can be useful for design engineers. The design charts are developed considering strength and serviceability conditions as specified by the IS 800:2007.