Lateral-torsional buckling strength of corrugated web girders – Experimental study

Abstract

Current standards and specifications do not provide specific design methods to determine the lateral-torsional buckling (LTB) strength of girders with trapezoidally corrugated web. In the international literature there are some previous investigations available focusing on the LTB strength of corrugated web girders. Based on numerical calculations analytical solutions have been derived in the past, however, there is a lack of experimental test results to prove or improve these design proposals. The authors performed an extensive experimental research program including eleven large-scale test specimens. All the test girders have different flange sizes, beside, having the same corrugation profile. The test specimens are loaded by pure in-plane bending having simply supported boundary conditions. The tested specimens have limited warping and rotational restraint at the supports. No web distortional type failure is observed. During the tests the longitudinal strains are captured in characteristic cross-sections and the displacements in vertical and lateral directions are measured as well as the rotation of the mid-span cross-section. The measured LTB strength of the test specimens is compared with existing analytical proposals regarding corrugated web girders and the differences are evaluated. It is observed that the imperfections have key role in the LTB behavior. Based on the experimental results buckling curve “b” from Eurocode 3 is preliminary proposed for the determination of the lateral-torsional buckling strength of trapezoidally corrugated web girders. The executed test program gives useful background to further numerical studies.