Study On The Fatigue Performance Of Orthotropic Steel Decks For Long-span Suspension Bridge Box Girder

With the development of highway industry,much more steel structures will be applied in the highway bridges.As an essential part of bridge steel structures,orthotropic steel decks are widely adopted in the large span bridges.Due to their sophisticated configuration,the fatigue issue of the critical details attracts the attention of numerous researchers and engineers.The paper focuses on the orthotropic steel decks adopted in the large span bridges and the following researches are been carried out:(1)The development of orthotropic steel decks is described and the issue of fatigue is put forwarded.(2)The fatigue fracture mechanics for steel structures,especially for welded structures,is been described and the causes of fatigue fracture are been analyzed in the respect of fabrication,structural configurations and the structural behavior.The evaluation and research methods of steel structure fatigue performance are described in details and the measures by which the fatigue performance can be improved are been investigated.The paper then illustrates the analysis process of steel structure fatigue performance in accordance with the Eurocode.(3)The fatigue performance of the five critical details of an orthotropic steel deck of box girder of a suspension bridge is been investigated by adopting the finite element method and the results show that the fatigue performance of the free edge of the tooth shaped diaphragms cannot meet the requirement of design period.(4)In order to relieved the fatigue issue of the free edge of the tooth shaped diaphragms,four strengthening schemes are been put forwarded and one best solution is selected for the manufactured box girder sections while one practical solution is been proposed for the non-manufactured box girder sections.