Shear capacity of stiffened plate girders with compression tubular flanges and slender webs

• The shear strength of CHTFPGs is investigated.
• The ABAQUS program as a FE software is used in this work.
• Eurocode 3 provides highly conservative shear predictions for CHTFPGs.
• A modified design shear method is suggested for the CHTFPGs.

In this paper, finite element (FE) investigation is conducted to study the shear behaviour of compression hollow tubular flange plate girders (CHTFPGs) using ABAQUS software. The compression and tension flanges are formed from tubular and flat plate, respectively. First, a comparison is made between the CHTFPGs and plate girders with flat flanges (IPGs). This comparison indicated that CHTFPGs provide higher strengths and consequently provide weight savings compared to IPGs. A parametric study is, then, carried out on simply supported CHTFPGs regarding the span length, the flange dimensions, and the thickness and the aspect ratio of the web. From this study, the key parameters affecting the behaviour and the strength of CHTFPGs are discussed. The shear strengths of the CHTFPGs are determined from the current FE models and then compared to the unfactored design strengths computed according to Eurocode 3. It is found that the predictions following the European specifications are conservative compared to the FE strengths. The FE strengths are also compared with the strength recently proposed by the current authors for girders with upper and lower tubular flanges (HTFPGs). The comparison indicates that the later strength is unconservative compared with the FE strengths. Accordingly, a design method is suggested to calculate the nominal shear strengths of the CHTFPGs based on their FE strengths and the strength results of additionally generated equivalent plate girders with upper and lower flat flanges (IPGs). The suggested design method is found to give more accurate predictions for the shear strengths of the CHTFPGs.