Research On The Static Behavior Of High Performance H-beam After Continuous Load Combined With Local Corrosion

With the rapid development of social and economy,China government has put forward a overall traffic planning.As a bridge project across mountains,rivers,lakes and seas,it is located in all parts of the motherland in the construction of road traffic.From the development trend of the world,high-performance steel with its advantages of high strength,light weight,high toughness,corrosion resistance and weldability will gradually become an indispensable bridge construction material in the future.In this engineering background,the durability of high-performance steel bridge in service has become a problem that needs to be concerned.In this paper,the coupling method of continuous load and electrified corrosion is used to the lower half section of high-performance H-shaped steel beam.Through experimental research and ABAQUS software finite element modeling method to analysis of the change rule of static performance after corrosion.Then,the pure electrified corroded steel beam is added to the comparative analysis of the corroded surface morphology of the steel beam,and Study the factors of stress state and no stress state respectively.The work summarized mainly includes the following:(1)In order to provide data basis for the comparative analysis of corrosion surface morphology,We designed and manufactured four Q550E high-performance H-beams,and carry out two kinds of electrified accelerated test of H-beam with or without continuous load.The static tests of corroded steel beams under two symmetrical loads are carried out to study on the change rule of mechanical properties of local corroded steel beams under continuous load.(2)Using Faro laser scan arm three-dimensional laser scanning measuring instrument to respectively obtain the surface morphology characteristics of corroded steel beams under continuous load and the surface morphology of steel beams corroded by pure electricity.Using the method of image fractal dimension calculation to distribution and depth of corrosion pits on the corroded surface of steel beams are expressed quantitatively.The fractal dimension of the surface morphology of steel beams with or without stress is obtained and compared.The corrosion degree of steel beam is described from the index of surface corrosion heterogeneity,and the effect of continuous load on the corrosion of steel beam is explained.(3)The mechanical properties of steel beam test results are analyzed,mainly from the failure mode of steel beam,ultimate bending capacity,load deflection curve,failure mode considering strain and plane section assumption judgment in loading process.Combined with the experimental phenomena and results,the ultimate bending capacity calculation formula based on the pure bending theory and its extension is derived,which provides ideas and help for the future calculation of steel beam bearing capacity.(4)Using ABAQUS finite element software,a three-dimensional geometric model of corroded H-beam is established,and the modeling process is simulated according to the actual test situation.From the four indexes of failure mode,ultimate bearing capacity,load deflection curve and overall stress distribution,the calculation results and test results of the model are compared and analyzed.The analysis results are in good agreement with each other,and the model has reference significance.