PSI - Issue 22

N. Makhutov et al. / Procedia Structural Integrity 22 (2019) 93–101 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig.5. Dependencies of stress and strain concentration factors on the magnitude of strain hardening exponent

The magnitude of strain hardening exponent is a key parameter that influences the values of K σ and K ε . Fig. 6 presents the dependencies of stress and strain concentration factors on the magnitude of nominal stress for a plate specimen with a central hole ( K t =3) for two types of structural materials: mild steel with low strain hardening ( m =0.08) and concrete with high strain hardening ( m =0.6).

b) m=0.6 (concrete)

a) m=0.08 (mild steel)

Fig. 6. Dependencies of stress and strain concentration factors on the magnitude of nominal stress for two types of materials with low and high strain hardening exponent

Fig. 7. Theoretical and experimental local strains for smooth ( K t =5,1) and notched ( K t =1,5 - 5,1) specimens

Fig. 7 presents plots of the maximum logarithmic strains at the notch root against net nominal stresses for smooth ( K t =1) and notched specimens ( K t >1) made of austenite heat-resistant steel 80 Х 18 Н 10 Т . The experimental data are