Theoretical and experimental determination of DFR-corrosion-influence-factors

The relationship of detail fatigue rating (DFR)-corrosion-influence-factors and aggressive environments was studied, which makes the DFR method under erosion environments for civil aircraft structures'fatigue analysis more applicable to different structure details and different service environments. The way was established to decompose DFR-corrosion-influence-factor into ground-corrosion-influence-factor and air-corrosion-fatigue-influence-factor. The relationship between ground-corrosion-influence-factor and corrosion time as well as the relationship of perplexing environment corrosion-fatigue-influence-factor and mono-medium corrosion-fatigue-influence-factors were studied. Experiments for typical influence factors testing were conducted and reported. The results show that DFR-corrosion-influence-factors are decreasing as the increasing of ground-corrosion-time and the aggravating of environments causticity. The influence of corrosion fatigue is much serious than that of ground-corrosion. The example of structure fatigue analysis with DFR method under corrosive environment shows the detail steps and data requirements. The analysis indicates that DFR of a given structure is reduced significantly by corrosion, and the influence must be taken into account properly in fatigue analysis.