Shear mechanism and design of small-scale tubular flange corrugated web girders

Abstract

This paper explores numerically the shear behaviour and web strength of a new type of corrugated web girders (CWGs) consisting of an upper tubular flange, a corrugated web and a lower flat plate flange. The current finite element (FE) models, simulate by ABAQUS software, are validated using the results of three new small-scale experimentally tested girders that have been recently published by the authors. Three main points are studied in this paper, namely the propagation of the plastic shear hinges (PSHs), the effect of the corrugation wavelength and the development of a new elastic design model for the girders. First, the girders are simulated to unveil their shear failure mechanism, focusing on the propagation of the plastic shear hinges (PSHs) that characterise the shear failure of conventional flat-webbed girders. Through comparisons between the tubular flange CWG and the corresponding CWG with flat plate flanges (called hereafter as the conventional CWG), it is found that PSHs occur in the lower flange of former girder at the ultimate load whatever the type of the shear buckling is, while the later does not show PSHs for cases failing by local or interactive buckling. The effect of the wavelength of the corrugation of the tubular flange CWG is secondly analysed and the results show that as the corrugation wavelength decreases, the shear capacity increases with the local shear buckling or interactive shear buckling, but this rule is not suitable for the global shear buckling mode. Finally the shear ratio of the tube to that of the entire cross-section is derived and the shear strength equation of the tubular flange CWG is provided and verified through comparisons with test results.