A discrete optimization process for the design of horizontal girders of rising sector gate using PIAnO

Abstract

Many small dams have recently been constructed on several major rivers in the Republic of Korea to utilize these water resources and control water flows. One such water body is the Gangjeong reservoir in the Nakdong River; a rising sector gate was mounted on this reservoir. The finite element analysis (FEA) confirmed the empirical design of the gate to be safe with minor modifications. However, the positions of the horizontal girders are critical in the design of a gate, and it is must be determined by a trial-and-error process. To find the optimal solution for the positions and thicknesses of horizontal girders in a rising sector gate, this paper proposed a new procedure using the commercial optimization package, PIAnO, as well as Pro-Engineer, Hypermesh, and Abaqus. The optimal positions of the horizontal girders are selected from 9 predefined positions. A special technique was developed and applied to change the discrete position set, such as (1, 4, 8) to a continuous dimensionless variable. For this, a FORTRAN program was written to convert the dimensionless variable to a set of position numbers, and vice versa.