PSI - Issue 28

NikolayA. Makhutov et al. / Procedia Structural Integrity 28 (2020) 1347–1359 N.Makhutov, D.Reznikov/ Structural Integrity Procedia 00 (2019) 000–000

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temperature and stress triaxiality arising in the notch zones on the local characteristics of the strength and ductility of the material (Fig. 1).

Nomenclature e max c maximum local strain at the notch root e p plastic strain e eq equivalent strain e normalized strain et e 

is stress (equivalent stress) at the strain rate е  and temperature t

0 eq e 

is strain rate during static tests;

0 e  i e 

is the strain rate under static loading is the rate of intensity of plastic strain;

fracture strain

e f

equivalent strain rate

eq e 

nominal strain yield strain

e n e y

plasticity reduction factor at the notch

D ec

yield stress reduction factor due to stress triaxiality at the notch

I c K t K σ K e

theoretical stress concentration factor

stress concentration factor strain concentration factor strain hardening exponent fracture stress in the neck ambient temperature

m S f

t

room temperature fracture energy equivalent stress

t 0

f 

σ eq

σ eqH

von Mises equivalent stress

et  

stress (equivalent stress) at the strain rate е  and temperature t

mean stress

σ m

σ max c

maximum local stress at the notch root

nominal stress ultimate stress yield stress

σ n σ u σ y



normalized stress

1 uniax c  first principal stress in case of the uniaxial tension upon which plastic yielding occurs triax c  first principal stress in case of the triaxial state of stresses upon which plastic yielding occurs 1 / i c c i c     relative principal stresses in the notch zone ϱ radius of the curvature at the notch vertex ψ f0 relative narrowing of the cross section at fracture Analysis of the states of stresses and strains of structural components at the notch zones in wide ranges of strains, strain rates and temperatures, as a rule, causes considerable difficulties. Closed form solutions are only available for a relatively small number of specific cases. In this regard, studies of the effects of the redistribution of stresses and 1