Orthotropic Analysis of Steel Deck–Girder–Rib Systems Subjected to Transverse Load

As one of the advanced modern techniques, orthotropic steel decks are widely used in bridge engineering. Because of its structural complexity, theoretical analysis of mechanical performances of the orthotropic steel bridge deck is very difficult. Therefore, in the past 50 years, a series of experiments and finite element analysis have been used to obtain the information. A steel deck–girder–rib bridge system subjected to the transverse load is investigated in this paper. The bridge deck is laid on four simply-supported girders at the four edges and is reinforced by ribs in longitudinal direction. The longitudinally stiffened deck is idealized as an orthotropic plate. The equivalent material properties in the longitudinal and breadth directions of the orthotropic plate are evaluated using micro-mechanics of composite material by treating the ribs as reinforcing fiber-beams. Governing equations for the deck–girder–rib bridge systems are established and are solved using Ritz method. The analytical solutions are substantiated by comparing with the classic solutions of an isotropic deck with fixed ends and with the finite element predictions. The analytical approach presented in this paper eliminates the very intricate and arduous kinematics study among deck–girder–rib and allows the bridge engineer to fast and convenient estimate the deformation in an orthotropic bridge deck.