Application Of Damage Mechanics On The Fatigue Damage Of Steel Bridge

In this paper, application of damage mechanics theory to study the evolution anddevelopment of the steel bridge fatigue micro-cracks, the first analysis of the previousstudies, the conventional method of steel bridge fatigue problems, and previousexperience, the application of damage mechanics from the point of view of themicromechanical damage analysis fatigue micro-crack initiation,. Brittle fracture ofsteel bridges fatigue failure is due to microcrack damage accumulation in the process ofcyclic loading, resulting in components. The first microscopic study of the morphologyof the fatigue crack so you can use damage mechanics, analysis of the micro-crackmorphology of the different steel components of the initial state characteristics. Studymicro-cracks in the role of external conditions,the damage evolution process and its impact on the macroscopic mechanicalbehavior, and then transition to macroscopic phenomena from microscopic cracks tomacroscopic characteristics and morphology study of crack propagation. And analysisof micro-crack formation to expansion into the critical state of the macro-phenomena toassess the remaining life of steel bridge. The same time, in accordance with the fatiguemicrocrack from conception to initiation, to the macro-crack, and finally lead tocomponent fatigue failure this line of thought to carry out the papers. Established amathematical model of fatigue micro-crack damage, and fatigue micro-crack stage ofmathematical discriminant model. Through the calculation of the mathematical modelobtained specific estimates on the damage to the component life. For a more detaileddescription of the expansion of micro-cracks, finite element analysis software ANSYS,the establishment of a simple steel bridge component model, and made a simplecalculation of the fatigue problem. To prove by calculating the component under highstress, very prone to fatigue micro-cracks, but also gives the curve of fatigue damageand the number of stress cycles.The purpose of the last of this paper is from the point of view of damagemechanics to analyze the fatigue failure of components, micro-cracks and extendedanalysis from the micro world, and through to the establishment of micro-crack stage ofthe discriminant model to predict component fatigue damage life expectancy. This paperwill establish a flow chart to assess steel bridge fatigue micro-crack propagation, the use of flowcharts, clearer to understand the fatigue micro-crack propagation, and to find outthe key components of fatigue from the large bridges, steel bridge fatigue assessment toprovide guidance.