Hysteresis Loops Resulting from Reloading-SWT and Morrow Model

6 Hysteresis Loops Resulting from Reloading-SWT and Morrow Model 

Numerical results obtained on a notched component made of the same steel of the previous sample problem has given the time history of Fig. 6.37 on the notch root. Determine the 

The initial ramp of the hysteresis loop is given by Eq. (6.3). The values of the three exponents n, b and c are known 

The value of the plastic modulus K is needed. The modulus can be obtained from the intersection of the interpolation line of Oa— p data with the vertical at p — Experimental results obtained using 14 hourglass specimens, Fig. 3.4a, having 0 — 6 mm and / = 18 mm are shown in Fig. 6.38 with the relative interpolation line. These results arrive to 10 % deformation to have a rather accurate extrapolation point at 8 = 1 whose value yields ffa= 1,210 MPa. Now the loading ramp can be derived. It goes from 0 to 0.004 mm/mm of deformation 

6 Strain-Based Fatigue Analysis Low Cycle Fatigue 

---