Coordenação de Aperfeiçoamento de Pessoal de Nível
Superior,001,Ricardo A. Hoffstaeter,Conselho Nacional de Desenvolvimento
Científico e Tecnológico, 001, Carlos Humberto Martins,
Project n. 408498/2022-6, Brazil.
This paper presented the results of numerical analyses on the fire resistance of composite columns with partially encased
steel columns (PEC). This investigation used 2D and 3D finite element models and assessed for the design method of
composite elements under compression according to the Annex G of Eurocode 4. New proposals were presented to
determine the buckling resistance of PEC under standard fire. The 2D and 3D numerical models were based on American
and European steel profiles. The 2D thermal model was used to improve the design method of the current version of the
Eurocode 4, enhancing the balance summation model, which is currently used to determine the plastic resistance to axial
compression and the effective flexural stiffness of the four components of the cross-section. The 3D thermomechanical
model used the temperature field for each fire rating time (30, 60, 90, and 120 min) and applied the incremental load step
solution method, based on the Newton–Raphson, to determine the buckling load of partially encased columns with 3 and
5 m, considering different supporting conditions. These results present a safer buckling curve when compared to curve ‘‘c’’.
