Fatigue strength reliability analysis of diesel connecting rod based on stochastic finite element method

In this paper, stress of a diesel connecting rod (CR) is analyzed by the pe rturbation stochastic finite element method (PSFEM). A fatigue failure crit erion of a diesel CR is also put forward with Corten-Dolan fatigue cumulati ve damage theory. Based on fatigue failure criterion and the results of sto chastic stress analysis, the advanced first order second moment (AFOSM) met hod is used for fatigue strength reliability analysis. It is shown that PSF EM is efficient and accurate in stochastic stress analysis by comparing wit h Monte-Carlo simulation. The analysis shows that the reliability of a cert ain type of diesel CR is 0.99917, which coincides with the statistical data from the factory. It is also found that operating parameters such as combu stion peak pressure and engine rotary speed have the greatest influence on CR reliability because of the large variances and high stress response sens itivity.