Nonlinear Thermal Analysis of Steel Sections with Boundary Element Method

Resumo

The fire safety is a topic that has been under discussion lately, mainly due to the last fires that have
befallen humanity and to which countless losses are linked. In this context, the role of fire resistance of structural
elements is essential for the security of buildings. Therefore, a non-linear thermal analysis of steel sections is
proposed with the Boundary Element Method. The partial differential equation of non-linear heat conduction is
linearized using the Kirchhof Transformation; the non-homogeneous term of the mentioned equation is
approximated by a series of radial basis functions variable, in order to control the conditioning of the interpolation
matrix and using the Dual Reciprocity Method. In addition, boundary conditions for heat exchange by convection
and radiation are introduced in the model, in order to simulate heat exchange when the section is subjected to
standard fire. Finally, in order to validate and compare, the temperature field obtained for two different steel
sections is compared with the results of the simplified method presented in NBR 14323; obtaining a good identity
of the solutions. The results reveal the validation of the constructed numerical model and the precision of the
simplified method for thermal analysis of sections of steel.