NON-LINEAR GEOMETRIC ANALYSIS OF DEFLECTIONS IN METALLIC TRUSSES

Resumo

Geometric non-linearity consists of determining the stresses and displacements of a structure
considering the deformed state of the structure after load application, and therefore the equilibrium
equations must be reformulated for each of these changes. The present paper, in this sense, has proposed
to elaborate a software capable of analyzing the deflections of a structure of the trellis type,
implementing the changes of geometry with each applied load step. In order to perform the calculations,
the Finite Element Method was used, and the algorithm was written in the Python programming
language. With the results obtained in the software developed, and through comparisons with SAP2000
V15, it was verified that the simplified approach of geometric non-linearity, which was implemented in
the computational program elaborated, is very close to the results of SAP2000 as the load increase
decreases. The results show that the lattice node analyzed with the greatest divergence between the
software had a decrease in the difference between the deflections of the two software from 5.61% to
1.89% when changing the number of load steps, from two to one hundred steps.