关键词: 复合材料, 刚度降, 损伤, S-N曲线

Abstract:

No matter composite laminates is subjected to static or dynamic load, damage is significantly complex. Accurate modeling for fatigue damage can reveal the damage mechanism of composite laminates. In this paper, based on the cumulative damage theory and stiffness reduction model, fatigue damage of the composite was divided into two stages by the twostage theory of the fatigue damage. The fatigue damage process of composite was established by a segmented function and twostage model of fatigue damage. The segmented function includes two kinds of difference functions, exponential function and linear function. By using the experimental data and least square method of multivariate function, the parameters of this twostage fatigue damage process model and the SN curve were obtained. The SN curve was compared with that of experimentation and classical model. And the results obtained by present method are in good agreement with the results of experimentation.

Key words: composites, stiffness reduction, damage, S-N curve