Neubers Rule-Cycle Reversal

A panel of carbon steel 10 mm thick, 15 mm wide carrying a center hole of 5 mm diameter is subjected to fatigue cycles from 0 to F ax = 28,000 N. the steel is that already considered in sample problem 4. Assess the strain and stress amplitude of cycling. The cyclic stress-strain characteristic of the material is that of Fig. 6.35 having Eq. (6.49). The stress amplitude of the cycle is 

Entering diagram of Fig. 7.4 with the steel property it is found that the notch sensitivity factor is = 0.75 that renders a notch factor kf — 2.86. With these data 

As suggested by Walker [42], it has been used the kf and the cyclic curve of the material. The Neuber hyperbola for the loading phase is shown in Fig. 6.44. The intersection with the cyclic curve yields the working point A relative to the loading phase whose coordinates are 

Dowling, N.E., Brose, W.R., Wilson, W.K. A discussion of local strain approach to notched member fatigue life prediction. Westinghouse Scientific Paper 76-1E7-PALFA-P1, Feb 1976 

Tucker, L.E., Landgraf, R.W., Brose, W.R. SAE Report 740279, Automotive Engineering Congress (1974) 

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