Small-scale laterally-unrestrained corrugated web girders: (I) LTB tests and numerical validation

The lateral–torsional buckling (LTB) of corrugated web girders (CWGs), which have been used extensively in bridges worldwide, is investigated in this paper. In consideration that available flexural strength proposals of CWGs have been based largely on numerical/theoretical investigations, besides the scarce of physical tests and the risk of collapse by LTB, three small-scale simply-supported CWGs specimens are designed and tested, and their results are presented in this paper. An innovative test setup, containing special loading plates as well as end and lateral supports, is prepared to ensure that the tests are under pure bending moment through the four-point bending without any stabilising or destabilising effect for the applied load. The main test parameter is the web depth of the girders, while other parameters are evaluated numerically in the companion paper. Accordingly, the related experimental works are currently introduced and several conclusions are drawn. The effect of the web depth is evaluated, which shows that the ultimate buckling moments of the girders, and also the stiffness, increase with the increase in the girder\u27s height. Moreover, the tests indicate that the too thin corrugated webs (CWs) may be affected by web distortion which may not be very obvious in the deformed configuration, even though CWs do not withstand longitudinal stress. The corresponding finite element (FE) models are then developed taking into account the elastic and inelastic buckling analyses. Through comparisons with the tests, FE simulations show good agreement and ability to provide the behaviour of small-scale CWGs. Accordingly, they are used to generate parametric studies in the companion paper with the goal of providing the fundamental behaviour of small-scale CWGs as well as appropriate design methods. Additionally, FE modelling outcomes confirm that the entire sections of CWGs do satisfy the plane section assumption