PROBABILISTIC METHOD FOR LOCAL STRESS AND STRAIN ANALYSIS

The components in practical engineering are always of uncertainties from material, geometry, loading, etc. The uncertainties result in the randomness of local stress, local strain and fatigue life. In this paper the probabilistic analysis of local stress and strain in low cycle fatigue is performed. The cycle stress-strain response (hysteresis loops) and the Neuber formula are both treated as probabilistic curves with random variables in Neuber method. The uncertainties of material, geometry, loading, etc., are characterized by random variables. Polynomials are constructed to evaluate the random local stress and local strain. The cyclic strain-life relation is treated as probabilistic curve. In the same way, the random characteristic value of fatigue life is obtained with the random theory of fatigue damage accumulation. An example is given. It is shown that the results in the example are agreeable to those from Monte Corlo simulation, indicating that the present method is simple and efficient.