Failure and thermo-mechanical stress analysis of the failed exhaust valve of diesel engine

It has been observed that diesel engine locomotives working in the railway sector in our country have caused various engine failures, material and labor costs due to too many valve failures in recent years. In diesel and gasoline engines, the combustion chamber and its components where the energy cycle takes place are exposed to high temperature and pressure. It is obvious that the negative effects of thermal shock, pressure and burnt gases resulting from the combustion reaction will cause wear and deformation of the valves. Since these abrasions will decrease the mechanical life of the material after a period of time, it causes gradual performance decrease in the engine, increase in fuel consumption and deterioration in emission values. In this study, thermo mechanical stresses in exhaust valve which is a critical part of a locomotive diesel engine are modeled and stress analyzes are performed. The results obtained were compared with the failure analysis data obtained from the experimental studies and it was found that the failure occurred in the part was due to erosion corrosion wear. Alternative solutions to prevent or delay damage are presented.