Robust optimization design for fatigue life

To reduce the scatter of fatigue life, a robust optimization model of structural fatigue life is presented based on stochastic finite element method (SFEM). Considering the effect for structural fatigue life caused by variance of design variables and other random variables such as structure dimensions, material parameters and loads, the problem is formulated as a multi-criteria optimization problem, in which both the mean structural fatigue life and the standard deviation of structural fatigue life are to be minimized. The structural fatigue life is limited between the lower fatigue life and the upper fatigue life in the constrain functions. Numerical results show that the suggested method is feasible and applicable.