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

摘要

In this paper, stress of a diesel connnecting rod (CR) is analyzed by the perturbation stochastic finite element method (PSFEM). A fatigue failure criterion of a diesel CR is also put forward with CortenDolan fatigue cumulative damage theory. Based on fatigue failure criterion and the results of stochastic stress analysis, the advanced first order second moment (AFOSM) method is used for fatigue strength reliability analysis. It is shown that PSFEM is efficient and accurate in stochastic stress analysis by comparing with Monte-Carlo simulation. The analysis shows that the reliability of a certain type of diesel CR is 0.99917, which is coincidence with the statistical data from the factory. It is also found that operating parameters have the greatest influence on CR reliability because of the large variances and high stress response sensitivity.