SHEAR BUCKLING EVALUATION IN STEEL PLATE GIRDERS WITH RIGID END POSTS SUBJECTED TO ELEVATED TEMPERATURES

The current study intends to analyse the behaviour of steel plate girders with rigid end posts subjected to elevated temperatures, aiming the assessment of the ultimate shear strength in case of fire. A parametric numerical study was performed involving a wide range of cross-section’s dimensions, plate girders’ aspect ratios and steel grades. Plate girders were numerically tested at both normal and elevated temperature, being considered three different uniform temperatures. The influence of the geometrical imperfections, as well as the residual stresses, was taken into account. Finally, the numerical results were compared to the Eurocode 3 (EC3) prescriptions, adapted to fire situation by the direct application of the reduction factors for the stress-strain relationship of steel at elevated temperatures. It was shown that the EC3 design rules should be improved because they are not conservative, conducting to unsafe results