Ultimate Load Behaviour of Steel-Concrete Composite Plate Girders with Inclined Stiffeners

This paper focuses on the ultimate load behaviour of steel-concrete composite plate girders with inclined stiffeners. For this research, non-linear modelling and analyses were carried out on ten simply supported composite plate girders using a commercial finite element software, LUSAS. The girders are of practical design size and subjected to a single concentrated load applied at the centre of the girder span. Effects of different inclination angles of intermediate stiffeners and web-depth to thickness (d/t) ratios on the post-buckling behaviour of the girders are investigated. Five different angles of stiffeners, measured from the bottom flange, were considered in the research, viz., 90 degrees, 75 degrees, 60 degrees, 45 degrees and 30 degrees while the web thickness, t(w) used in this study are 2 mm and 3 mm. With the effects of such inclinations, the variations of ultimate load, load-deflection response and failure characteristics were obtained. The load carrying capacity was found to rise significantly of about 32%, as the angle of inclination reduced from 90 degrees to 30 degrees. The ultimate strength of the composite girder also shows a maximum increase of 28%, when the web thickness, t(w) rises from 2 mm to 3 mm.