Thermo-mechanical stress analyses of an aluminum alloy piston using thermal resistance circuit model

Piston has to withstands thermo-mechanical cyclic stresses in a wide range of engine operating conditions. The thermo-mechanical stresses distribution enables us to optimize the piston design at lower cost Thermo-mechanical stress analyses of an engine piston used in a gasoline engine was studied. The boundary conditions of thermal loads of piston obtained by thermal resistance circuit model and GT-POWER and MATLAB software products. The thermal analysis results showed that the piston crown center withstands the maximum temperature. The results of finite element analysis (FEA) indicated that the stress has the most critical values at the upper portion of piston pin and piston compression grooves. The numerical results showed that the stress maximum occurred at the upper region of piston pin. The results of the Von-Mises and Tresca criterions proved that the upper region of piston pin and ring grooves are critical areas. The distribution of the safety factor demonstrated no critical point in the piston, and the minimum safety factor of 1.1061 occurred in the upper area of piston pin. The results of the FEA are match with experimental damaged piston in these regions.