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Fig. 1.3 The history of the loading at block proportional and non-proportional deformation
• the third block includes 50 loading cycles with the amplitude of σ 11 = 248 MPa
and average stress σ
aver
11 = 78 MPa.
Figure 1.4 depicts the deformation curves, constructed in the strain path on the
basis of the numerical results.
For the loading history, presented in Fig. 1.3b, the stress amplitude σ 11 in blocks
at constant stress σ 12 with the amplitude
√
3σ 12 = const was changed as follows:
• the first block consists of 50 loading cycles with the amplitude of σ 11 = 248 MPa
and average cycle stress σ
aver
11 = 78 MPa;
• the second block includes 50 loading cycles with the amplitude of σ 11 = 248 MPa
and average stress σ
aver
11 = 117 MPa;
• the third block consists of 50 loading cycles with the amplitude of σ 11 = 248 MPa
and average stress σ
aver
11 = 78 MPa.
Figure 1.5 presents the results of comparing the calculated and experimental
curves of the average strain (axial and shear) as a function of the number of loading
Fig. 1.4 Computed deformation trajectories in the strain space