DESIGN AND FATIGUE LIFE EVALUATION OF PISTONS FOR HIGH BMEP DIESEL ENGINES

To meet the fatigue life requirements under high specific engine loading two piston design approaches are discussed. Due to advanced fatigue design and technology including internal piston cooling the aluminum piston is an optimum solution in a mep range of 12 to 17 bar. For higher rating a nodular cast iron piston design - also using internal cooling - is presented in detail. Engines with cast iron monobloc pistons are running nowadays at mean effective pressures of 16 to 22.3 bar. Un upper limit of this piston design has not been reached. Based on finite element analyses fatigue life predictions are included for two examples.