Deformation And Stress Simulation For The Piston Of Internal Combustion Engine By Using 3-Dimensional FEM

The piston is one of the key parts of the internal-combustion engine,the structure of piston and its working environment are very complicated. In working condition,various load,such as high gas-pressure,inertia force,side force and connecting rod force, act on the piston and produce mechanical stress and deformation.The high temperatureof chamber makes piston temperature distribution non-symmetry,causing the piston to produce heat stress and heat deformation. So the combined analysis of deformation and stress caused by thermal and mechanical load is important for improved design of piston structure.The purpose of this thesis is to study the stress and deformation of piston under combined influence of the thermal load and mechanical load. First,the piston geometry model is established by using 3D graphics software, whichcan be transformed into finite element analysis model in 3D finite element software. Then the mechanical load of piston is determined. The stress and deformation of piston under the action of the mechanical and thermal loads and the effect of thermo-mechanical coupling are analyzed,and the side thrust force of piston skirt is taking into consideration during analysis . Results show that the piston thermo-mechanical coupled stress is mainly influenced by mechanical load and coupled deformation is mainly influenced by thermal load.The piston deformation takes the form of non-axial symmetry distribution,there is a change of piston skirt profile after deformation. The results of this research could provide foundation for improving the design of piston.