Corrosion Fatigue Analysis And Improvement Of Structural Measures For Suspender Of Arch Bridge

In the past,the construction of arch bridge many have taken the boom through anchoring to suspend the beam,the form of the beam was some small T beams in the early years,in recent years the steel mixed beams are widely used,and there is no set beam.This makes the whole arch bridge girder and bridge surface integrity is not good,stiffness is low,the overall power performance of the bridge is also relatively unstable,will cause the boom amplitude increase,especially for the problem of boom fatigue.At the same time,the actual construction of the arch bridge boom produces large and small different diseases,such as surface rust,PE protective sleeve cracking,boom anchor box into the water and other serious problems,these problems will lead to the boom rust problem,serious cases will produce stress corrosion.Then,under the combined action of fatigue and corrosion,the corrosion fatigue problem of the boom will be produced.Therefore,this paper first comprehensively analyzes the force performance of the medium-class arch bridge,and then analyzes the fatigue performance of its boom,and the second is to analyze the degree and distribution of its rust damage from the local place of the boom,and to analyze the fatigue life of the boom.Starting from the engineering background bridge Evergreen Bridge,the model of the span finite element is established,the vehicle load is selected and the calculation model is calculated and the bridge unevenness is reasonably simulated,and the bridge coupling vibration analysis and the stress amplitude of the bridge are analyzed by ANSYS and MATLAB program,and the stress amplitude of the suspension bar is obtained.Through the analysis,it is found that the stress of the long boom in the span is smaller than that of the short boom at the arch foot,and the distribution is increasing.The results are calculated and observed as the effect of the vehicle speed and bridge unevenness on the stress amplitude of the boom,and it is found that the difference of the bridge surface is,the greater the pressure of the boom,and the change of vehicle speed has a particularly significant effect on the stress amplitude of the boom.Then,the fatigue performance of the boom is analyzed mainly from the different structural measures of the arch bridge.By adding vertical contact,it is found that the fatigue stress of the boom is greatly reduced.By pouring cement mortar in the gap of the boom,it is found that the stress amplitude of the boom is also reduced.By changing the weight of the beam,found that the lower the beam,the stress amplitude of the boom will be increased,but also consider the impact of the vehicle through the telescopic seam,found that the lifting bar stress at the telescopic seam has a certain increase,due to the unevenness of the telescopic seam,will increase the amplitude and power effect of the boom,resulting in a greater stress amplitude.Finally,starting from the problem of local rust of a single steel wire in the boom,the influence of the size,shape and quantity of a single wire corrosion pit on its stress concentration is analyzed,and the fatigue life of the single wire of the boom is analyzed through the DESIGNLIFE self-programming program.Finally,it is found that when the local rust pit exists,the fatigue life of the single steel rod of the boom will be greatly reduced.At the same time,the more complex the shape of the rust pit,will cause a greater coefficient of stress concentration,fatigue life will be reduced accordingly.Finally,considering the interaction between the boom will increase the stress of the boom wire and adversely affect it.