Manson-Coffin and Basquin Curves

6 Strain-Based Fatigue Analysis Low Cycle Fatigue 

Note that the exponents b and c are the slope of the two components, plastic and elastic, of the total life. 

Knowing exponents b and c it will be possible to infer the cyclic strain hardening exponent n from Eq. (5.33) or (6.9) that must yield the same value 

The small difference between the two values of n obtained from b and c respectively shall not come as a surprise considering the approximate character of the linear interpolations. About the plastic modulus K, it can be inferred from Eq. (6.2) in different ways. A first evaluation is 

The second evaluation is obtained from the interpolation of experimental cyclic stress-strain curve Ca — Sp shown in Fig. 6.33. The procedure yields 

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