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°, 75°, 60°, 45° and 30° while the web thickness, tw 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° to 30°. The ultimate strength of the composite girder also shows a maximum increase of 28%, when the web thickness, tw rises from 2 mm to 3 mm.