关键词: Miner准则, 疲劳寿命预测, 灰色理论, GM(1,1)线性模型, GM(1,1)幂模型

Abstract:

The fatigue life for arm structure of hydraulic excavator was influenced by many uncertain factors because of the complex impact loads were applied to it. Firstly, the Miner's rule was used, and the fatigue life of work device of hydraulic excavator was predicted based on experimental load spectrum and the finite element method. Then the internal consistency of the changing process of structure fatigue life and the grey theory prediction model was researched, the grey GM model of fatigue life prediction of hydraulic excavator's work device was established, the fatigue life of  hydraulic excavator's arm structure was predicted by using two forms of GM model, the linear model of GM(1,1) and the power model of GM(1,1) respectively. Three kinds of prediction methods, the Miner's rule, the linear model of  GM(1,1) and the power model of GM(1,1) were analyzed and compared, it is shown that the predicted results of three methods are basically identical, the error of gray system model is decreased obviously compared with the model of Miner's rule, and the nonlinear power model has higher predictionprecision. Because the nonlinear factors were considered in gray power model of GM(1,1), the gray power model of GM(1,1) is more suitable for the structure fatigue life prediction of hydraulic excavator's work device.

Key words: Miner rule, the fatigue life prediction, grey theory, linear model of GM(1,1), power model of GM(1,1)