Moment gradient correction factor and inelastic flexural–torsional buckling of I-girder with corrugated steel webs

Corrugated steel plates have several advantages such as high resistance for shear without stiffeners, minimization of welding process, and high fatigue resistance. To take advantage of these benefits, several researchers have attempted to use corrugated steel plate as a web for I-girders. The flexural–torsional buckling is the major design aspect of such I-girders. However, the flexural–torsional buckling of the I-girder with corrugated steel webs still needs to be investigated especially for a real loading condition such as non-uniform bending. This paper investigated the flexural–torsional buckling strength of an I-girder with corrugated steel webs under linear moment gradient by using finite element analysis. From the results, it was found that the buckling behavior of the I-girder with corrugated steel webs differed depending on the number of periods of the corrugation. Also, a simple equation for the moment gradient correction factor for the I-girder with corrugated steel webs was suggested. The inelastic flexural–torsional buckling strength of the I-girder with corrugated steel webs was then discussed based on current design equations for ordinary I-girders and inelastic finite element analysis considering initial imperfection and residual stresses.

► Flexural–torsional buckling (FTB) of I-girder with corrugated steel webs was studied. ► Elastic FTB behavior differs depending on the number of periods of the corrugation. ► An odd number of half corrugations leads to bifurcation buckling and it is desirable. ► Cb for I-girder with corrugated steel webs under linear moment gradient was proposed. ► Finally, inelastic FTB strength of I-girder with corrugated steel webs was suggested.