MECHANICAL ANALYSIS OF THE SANDWICH PLATES METHOD FOR STRENGTHENING FATIGUE CRACKS IN ORTHOTROPIC STEEL BRIDGE DECKS

The orthotropic steel deck is more and more widely used in bridges. But with the economic development, fatigue cracks in orthotropic steel bridge decks occur with the increasing of traffic volume. The sandwich plates method for strengthening fatigue cracks in orthotropic steel bridge decks is a relatively new method for bridge strengthening. This paper gives a brief introduction of the sandwich plates method and its application. Using finite element software ANSYS and ABAQUS, several kinds of elements were compared to obtain a reasonable and economical finite element model, which is suitable for simulating the sandwich plates. Vehicle load was applied according to General Code for Design of Highway Bridges and Culverts. The sandwich plates method was proved effective through the analysis of non-strengthened and strengthened orthotropic steel bridge decks. The stresses of the steel bridge decks were greatly reduced due to the sandwich plates strengthening method. In addition, parametric analysis of the elastic modulus of the middle layer was carried out, and the results indicted its effects on orthotropic decks' bearing behavior. Finally, a reasonable method for strengthening fatigue cracks in orthotropic steel bridge decks was put forward, so as to guide experimental research, as well as engineering design and practical operations of strengthening steel bridges.