Implementation of simplified second order estimation method from NBR 8800/2008 as support of structural analysis learning

Resumo

Structure analysis aims to obtain appropriate responses like displacements and internal forces in
structures. The results are used in limit state design method in order to maintain levels of reliability and safety in
structural engineering design. A global structure analysis may be conducted in a geometrically linear approach,
also known as a first order analysis, where the structure responses are obtained through equilibrium in an
undeformed configuration, or also in a geometrically nonlinear approach, in which additional effects (so-called
second-order effects) are determined in a deformed configuration equilibrium. NBR 8800/2008 addresses the
recommendations for second-order analysis in steel structures, presenting the possibility of both simplified and
rigorous geometric nonlinear analysis. In this context, the standard recommends the simplified method known as

amplification coefficient method to determinate, through an initial first order analysis, the approximated second-
order effects. In this context, this work introduces an application developed using Python language to assist steel

structure analysis learning. The program presents a first-order and a simplified second-order analysis using direct
stiffness method and the amplification coefficient method respectively. An interface is implemented in order to
become a useful and easy-to-use tool. It is also presented a comparison between the results from a rigorous
geometric nonlinear analysis, using the software AcadFrame, and the simplified method aided by the developed
software both applied to the same steel structure example.