A test series was carried out and reported in a corresponding paper on slender aluminium alloy sections, loaded in compression at elevated temperature. This paper gives the results of simulations of these tests with a finite element model. For this purpose, a novel constitutive model for fire exposed aluminium alloys is used. The critical temperatures obtained with the finite element models agree well with those of the tests (average difference 1 °C, standard deviation of 7 °C). The developed finite element models are used for determining the maximum plate width over thickness ratio at which the full plastic capacity is obtained before the plate buckles.