Experimental study on the lateral-torsional buckling strength of trapezoidally corrugated web girders

摘要

Current standards and specifications do not provide design methods to determine the lateral-torsional buckling (LTB) strength of girders with trapezoidally corrugated web. In the international literature there is only a limited number of 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. Therefore, the authors performed an extensive experimental research program in the Structural Laboratory of the Budapest University of Technology and Economics 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 buckling length of the specimens is 6000 mm with limited warping and rotational restraint at the supports. During the tests the longitudinal stresses are captured at characteristic points and the displacements in vertical and lateral directions are measured as well as the rotation of the middle cross-section. The measured strength of the test specimens is compared to the analytical proposals regarding corrugated web girders and the differences are evaluated. Based on the experimental results an improved design method is proposed for the determination of the lateral-torsional buckling strength of trapezoidally corrugated web girders.