PNBMaster

After familiarizing with prestressed structures, I was surprised how many iterations an engineer must go through while dimensioning prestressed beams. Additionally, as those calculations are carried out for numerous beam sections, only after their completion it could be known whether the assumed beam geometry was chosen correctly. Even if this is the case, optimal beam geometry is not assured.

I developed an algorithm that provides the best possible optimization for this beam type. User is not even supposed to enter starting dimensions. He is expected to enter information about load, material, prestressing friction parameters, beam slope and section iteration step. To find the optimum geometry, unit price of concrete and prestressed cables is chosen as limiting value. Algorithm provides prestressed beam geometry that has appropriate stress condition in all its sections and has the lowest possible price.

The code is based on variations of all relevant section geometry dimensions and cable forces. This results in vast amount of iterations which can exceed a couple of billions and last over ten minutes on modern quad-core computers. However, the process is performed only once, and the optimum design is guaranteed. Engineer can make sure of that by checking the resulting diagrams.