On Coupled Thermal-Mechanical Temperature And Stress Distribution Analysis For 8L265 Diesel Engine Piston

The piston is the heart of the internal-combustion engine. Whether it does work normally concerns the engine’s working dependability. Also, it will affect the use durability and emission performance greatly. We all know that its working environment is very badly, not only does it endure the high temperature, but also the mechanical load including the high gas-pressure, periodic load and frictional force. Heat and mechanical load can produce mechanical stress and distortion. The fuel burning in the combustion chamber produces high temperature and causes the temperature of the piston head increased. Both of them produce heat stress and heat distortion. Two kinds of load effect at the same time the piston will make the piston appear some work reliability problems, like crackle, scuffing of cylinder bore and piston-ring gluing and so on. So, we should consider the piston’s performance when designing. Usually, the finite element method is a effective method of calculating the performance of piston. The result including distortion and comprehensive stress distribution situation under the act of mechanical and heat load together can make a contribution to improving piston’s structure. It is important for improving the piston’s dependability.Figure calculation is valid method of the finite element analysis developed since nearly half a century. For the research of piston, foreign countries got many progress and carried out new method, but our country is later comparatively.The piston model built up by 3D graphics software in this text, then transmitted into finite element software ANSYS. It calculated the heat boundary and determined the setting of the lotus boundary condition and constraint. Besides, it got the result of stress and distortion under the function of mechanical and heat load.From the results we know that the piston’s temperature decreased due to the cooling oil antrum. The stress and deformation in the coupling filed is the result of the two load’s interaction, not the simple superposition. The maximum stress appeared in the piston pin seat when the two load coupled, and the mechanical load is the main factor. In contrast, the heat load plays a great role on the head of piston. On the whole, the result of the strength can meet the demand of designing.