چكيده به لاتين
Within the railway industry, Because of the fact that the most important and main goal is to maintain the safety, health and comfort of passengers, this sensitivity is becoming more apparent. Rail surface defect is one of the most common issues. Today, rail surface repair is done in different ways. One of the cheapest and simplest of these methods is manual welding of the damaged surface. In the present study, the main purpose is to investigate the residual stresses resulting from manual electrode method of the damaged surface of the UIC60 rail. First, the heat from welding is simulated using a subroutine Dflux in Abaqus software as a mobile heat source with Goldak thermal model, and then the resulting residual stresses are analyzed through temperature-mechanical coupling. Finally, by considering three important parameters in welding on the surface of the rail with a failure depth of 2 mm that were effective in residual stresses, the best and most effective way to reduce residual stresses has been introduced. According to the studies, it can be concluded that; 1. With cooling between welding passes, residual stresses are generally reduced, but the effect of cooling for 5 seconds is better than cooling for 10 seconds. 2. Cooling has no effect on transverse stresses. 3. Preheating on transverse stresses and longitudinal shear stresses. 4. Changing the speed of electrode movement and applied heat flux has a significant effect on reducing longitudinal and transverse residual stresses.
