Volume 1, Number  1, Jan-July 2000

      Minimum Cost Design of Rectangular Reinforced Concrete Section Using System Simulation

Ghulam Bashir Pirzada, Abdullah Saand, and Nazir Ahmed Durrani

6.      

Abstract:

A simple and an efficient procedure is suggested for the minimum cost design of singly reinforced rectangular beams based on strength design method; ACI-318/ 95. The cost function of the beam based on unit costs of formwork, specific concrete mix and steel and related to the depth and, steel ratio as design variables, is appended with the Lagrangian Multiplier representing the effect of equilibrium equation for flexure and consequent upon differentiation for minimum cost, results into nonlinear simultaneous equations which thus simulate the system. Through the application of the Newton-Raphson method, numerical determination of partial derivatives and Gauss Elimination method, these simultaneous nonlinear equations are then solved on digital computer to yield the least cost of the beam.