Finite Analysis Of Piston Strength And Deformation Based On Thermo-Mechanical Coupling

In recent years, the maximal combustion pressure and gas temperature in the combustion chamber has been increased significantly with the increasing power density and rostating speed of diesel engines, which aggravates the loading situation of aluminum alloys. Piston is the key component in diesel engines that has to endure high temperature and pressure. Damage caused by thermal-mechanical coupled loading limit increase to strengthen the capacity of the engine. Due to the combined effect of load region, structure, constraints, and the cooling medium, which finally influence the rate of thermal load and mechanical load on fatigue damage behaviors.In the present paper, performance simulation software ‘GT-Power’is used to simulate different operate conditions happened on engines. Heat transfer coefficient, temperature, and pressure values under different crank angles can be obtained through performance simulation.Finite element software ‘ABAQUS’ is used to acquire piston’s temperature, stress, strain distribution under different operate conditions. The stress under thermal load, mechanical load and thermal-mechanical load is obtained latterly. Finally, the regular of stress distribution can be obtained.Based on the continuum damage mechanics, the creep damage and fatigue dmage are accumulated and the creep-fatigue life prediction model has been constructed. Then fatigue damage are calculated with the proposed model. The results show that the thermal load at the throat contribution rate of 82.6%, the pin hole mechanical load contribution was 69.7%.