Otimização da quantidade de longarinas e transversinas em pontes pelo método dos elementos finitos

Abstract

Bridges are structures through which we are able to cross large obstacles such as valleys and rivers, allowing the continuity of a road or path, facilitating the locomotion, thus, it is an indispensable construction in our society. One of the characteristics that most influences its construction is the economic issue, due to its cost of execution, thus, it is of great value, a dimensioning in which the structures of the bridge to be built have already been idealized initially to generate the lowest efforts and deformations, due to the most optimized arrangement of the amount of Beams and Cross-Beams. In light of the above, this study analyzed twenty four bridge models, in which the number of beams varied from two to five on the same bridge and the use of intermediate cross-beams from situations without stringers to those with up to two stringers. The calculations of this study were performed using the Finite Element Method, through the CSiBridge V24 software, which allowed quantifying the bending moments, shear forces, torsional moments and vertical displacements. The studies showed that both for bending and shear moments the placement of cross-beams did not cause major changes with no need to add them to the structure, however an increase in beams, especially from two to three beams, showed the best results in terms of the reduction of these efforts. On the other hand, for torsional moments and displacements, the characteristic that presented the most optimized model would be to introduce intermediate cross-beams, which have been shown to decrease the values of these efforts and deformations, due to their characteristics of providing better locking and stiffening the structure, at the same time, for torsion, it was observed that the smaller the number of beams, the lower the obtained moment, while for displacement, the best case would be the one with three stringers, due to a third beam being added in the center of the bridge, decreasing the deformations in this region. Thus, the most optimized solution covering all the parameters previously mentioned, and with the characteristics studied, would be a bridge model containing three beams and with an intermediate cross-beam.