Hamid Eskandari-Naddaf - Associated professor of Hakim Sabzevari University, Iran
Ali Kooshkaki - MSc student of Hakim Sabzevari, Iran

This paper presents a practical and efficient approach to optimize the pre-stressed concrete beam with the best placement of tendons (most minimal eccentricity values). For this purpose, objective function was applied that prepared an effective relationship between the pre-stressed concrete beam and the values of tendon s eccentricity. On the other hand, the designation of prestressed indeterminate beams is developing with uniform cross-section method. Due to the use of high resistance materials and the effective presence of tensile forces in pre-stressed concrete, there is less need for materials and, on the other hand, despite the high cost of materials and the need for specialized workers, it is felt necessary to optimize pre-stressed sections. Since the equilibrium equations of the pre-stressed sections are polynomials and can’t be solved by linear programming, a geometric method could be used for optimization. In this paper, the geometric method used to optimize pre-stressing force and achieve to the best placement of tendons for rectangular cross-sectional shape.

Optimization Pre-Stressed Beam; Geometric Programming; Minimum Pre-Stressing Force; Placement of Tendons.