In The Existing Highway Bridge Steel Fatigue Performance And Residual Life Assessment

In recent years,with the development of our country’s economy,the increase of urban traffic,many of the founding of the early construction of steel bridge under the existing traffic conditions in every day bears the high low frequency of cyclic loading,this paper use the fatigue life evaluation method,the study of China’s current steel bridge fatigue,Taking Chongqing jialing river horn Tuo bridge(steel truss) for a study on the specific engineering example,Research work and conclusions are as follows:(1) Steel Bridges noted in anti-fatigue design theory of infinite life design requires the use of stress control member at a very low level, the characteristics of the material does not ful y reflect the infinite life is not economic; safe life design using S-N curve segment decline based Miner cumulative damage theory from now widely used; structural damage tolerance design admit the existence of genetic defects, relatively close to the real situation.(2) the study of highway steel bridge fatigue performance, and combining with foreign standard(AASHTO,Eurocode),through the comparison and analysis,it is concluded that the advantages and disadvantages of our country highway bridge steel specification.(3) using the finite element to establish three-dimensional model of the Chong qing jialing river horn Tuo bridge,Determined by the maximum stress amplitude of tension components damageable parts of the bridge.(4) using the finite element,to simulate the Chongqing jialing river horn Tuo bridge damageable parts locally,Get the bridge under static load anti-fatigue performance is good.(5) the investigation of real bridge traffic load, and using Monte Carlo method to simulate the actual traffic, the influence line load, the rain flow count method to count statistics, access to artifacts to simulate the stress spectrum, Then the Chongqing jialing river horn Tuo bridge is obtained by using the traditional method for evaluating the fatigue life of the residual fatigue life of vulnerable components.