The performance of tapered composite plate girders loaded in shear: An experimental and numerical investigation

Abstract

Composite non-prismatic girders have been used in modern bridges worldwide. Experimental and theoretical studies were performed to investigate prismatic steel plate girders. However, research on evaluating the behavior of tapered composite plate girders is limited. This study examines the ultimate shear capacity of tapered composite plate girders. Five large-scale girders, one prismatic and four tapered, were tested under a single-point load at midspan to determine their ultimate shear capacity and shear failure mechanism. The taper angles (0°, 5°, 10°, and 15°) and web openings were considered. The failure mode of the tapered plates was also studied. In addition, a numerical simulation was performed to evaluate the influence of the shape and size of the web openings on the shear capacity of the tapered composite plate girders. The results indicated that the taper angles significantly affected the stiffness and ultimate load of the girders. The magnitude of the maximum drop in the shear capacity of the taper degree of 15° was approximately 18.7%. It was also observed that the web opening decreased the capacity of the girder because the rigidity of the web decreased. The decrease in strength of the girder with web opening was 27% compared with the strength of the sold web. Moreover, the validity of the developed finite element (FE) models was verified using corresponding experimental specimens. The results indicate that the FE model can predict the ultimate shear capacity of the tapered composite plate girders.