Experimental study on buckling behavior of orthotropic steel deck with slender open ribs for large span suspension bridges

This paper presents an experimental and numerical study of the buckling behavior of the orthotropic steel deck with slender open ribs for the Zhangjinggao Yangtze River Bridge. Eight specimens consisting of four longitudinal stiffeners and a top deck plate were fabricated and subjected to axial compression loading tests. Finite element simulations and a parametric discussion were carried out using ANSYS software. Experimental results demonstrated that the axial buckling failure mode was characterized by stiffener tripping before the yielding of ribs. The post-buckling stage showed a certain ductility when the ribs did not collapse simultaneously. A buckling strength of 323 MPa was obtained from the tests, which reflected a sufficient safety margin compared to the working stresses in the real bridge. The numerical results agreed reasonably well with the tests. The study showed that the ratio of buckling stress to yield strength ranged from 0.72 to 0.84. Besides, geometric imperfections, residual stresses, and vehicle loads merely degrade the buckling strength to a small extent according to the parametric discussion. •Axial compression tests were conducted to study the buckling behavior of orthotropic steel decks with slender open ribs.•Local lateral torsional buckling of the stiffener dominated the instability failure mode.•The buckling strengths reflected a sufficient safety margin compared to the working stresses in the real bridge.•The influences of geometric imperfections, residual stresses, and vehicle actions were numerically discussed.