Experimental behaviour of a thermally restrained plate girder loaded in shear at elevated temperature

This paper outlines an experimental investigation of twelve simply supported steel plate girders subjected to shear loading at elevated temperature. Three different series of steel plate girders have been tested at three constant elevated temperature levels. Additional axial restraints were applied onto beams to simulate the thermal restraint effects of adjacent cooler parts of steel-framed structure in fire. Based on test results and observations, the pre- and post-buckling behaviours of plate girder web panels at high temperature were discussed. In addition, finite element modelling of the web panels was conducted and numerical models generally agreed well with test results. It was observed that the ultimate shear capacity decreased significantly under a thermal restraint effect.