Optimum Design of Prestressed Concrete Beams

One of the motivations in optimizing structures is to reduce the overall weight, which often results in reduced material cost. Efficiency implies minimum cost or minimum weight while satisfying a variety of strength and stiffness requirements. In all engineering problems, designers try to find solutions giving good performance, which satisfy several requirements. Using optimization techniques, engineers can obtain the optimum results, within the imposed conditions. Structures designed in this way are safer, more reliable and less expensive than the traditional designs.

This paper describes how MSExcel is utilized to organize, manage and direct for solving and optimizing a pre-stressed concrete beam section. To evaluate the stress and deflection, SAP2000 structural analysis software is used. This numerical design optimization provides the designer with a computational tool that finds the best design, based on predefined performance requirements. MSExcel optimizer automatically makes changes to problem parameters that are allowed to vary, referred to as design variables and performs a new analysis (linear or non-linear) to evaluate the influence of the changes, repeating the process until the design that best satisfies the performance requirement is found. The optimized results are then compared with manual design results.