Q2. How is the cyclic stress-strain curve obtained?
after a few blocks of loading cycles, the response stabilises and the cyclic stress-strain curve can be obtained from half of a stable block.
Q3. What is the way to measure the strain life of a steel?
A method to correlate axial and bending test results through an energy criterion has been established, demonstrating that the strain-life relationship of Eq. (1) can be derived from testing in either configuration.
Q4. How was the energy to fracture calculated?
The energy to fracture per unit volume of material in the axial tests was obtained by numerically integrating the areas under the stress-strain hysteresis loops, while in the bending tests the same was calculated by integrating the areas under the moment-curvature hysteresis loops divided by the width and thickness of the specimen.
Q5. What is the effect of cyclic hardening on the elastic and plastic components?
Although the total strain amplitudes were kept constant throughout the tests, the amplitudes of the elastic and plastic components changed due to cyclic hardening of the materials.
Q6. What are the three approaches for establishing cyclic stress-strain curves?
Three approaches for establishing cyclic stress-strain curves have been employed in previous studies, referred to herein as the multiple-step, incremental-step and companion methods.
Q7. What are the different failure modes of the bending specimens?
As for the axial specimens, the fracture surfaces of each of the bending specimens have also been examined to categorise the failure into ductile, mixed and fatigue modes.
Q8. Why were the two stainless steel grades grouped as the same material?
Owing to the similarity in chemical compositions and specified mechanical properties [19], the two stainless steel grades were grouped as the same material in this study, and indeed, exhibited similar behaviour.
Q9. What is the number of reversals to failure?
The number of reversals to failure is plotted against elastic and plastic strain amplitudes on a log-log scale for each material and shown in Figs 15-17.