Study On Fatigue Performance Of Medium Span Emergency Repair Steel Beam For Railway

The research is slow on the fatigue performance of railway steel beam in our country,and the design specification is relatively old.According to the characteristics of emergency repair of steel beam fatigue problems,it is so lack of knowledge,technical level in many areas of our country,which can not meet the requirements of emergency steel beam.In recent years,because of the simple structure,rapid assembly and disassembly,random collocation,repeated use and multi use,the steel beam is widely used in our country.However,due to the lack of scientific guidance of the relevant norms,the fatigue failure of the steel beam is very easy to happen.Therefore,it is very necessary to carry out the research on the fatigue life evaluation and anti fatigue design of steel beam for emergency repair.According to "design of steel structure","railway bridge repair(construction)technical regulations" and the relevant theory,This paper uses software ANSYS and other auxiliary software to study the fatigue performance of the steel beam of the middle span in railway:Firstly,aiming at the deficiencies of anti fatigue design of current specification in China's railway for emergency repair steel beam,summing up the existing methods of the resistance fatigue design,this paper put forward a simple method on the resistance fatigue design of the emergency repair steel beam.Secondly,aiming at the typical stress areas of the important parts of the emergency repair steel beam,using the load stress amplitude caused by DF 4 locomotive and C60 gondola car,the paper finds out its fatigue life thought fatigue analysis,and through comparativing the result of fatigue life in the two kinds of load conditions,the result is that the emergency repair steel beam has the same fatigue life in five gondola car or one locomotive.Finally,according to the characteristics of the same kind of the emergency repair steel beam in the repair process,which is random interchange and repeated application.Based on the nominal stress method and probability theory,this paper seeks out a calculation method to solve the fatigue life of the whole repair beam with the load is the locomotive with hanging any number of C60 gondola cars,and assessments the fatigue life of the whole repair steel beam and member bar with the load is the locomotive with hanging 60 C60 gondola cars.