PSI - Issue 39

N.A. Makhytov et al. / Procedia Structural Integrity 39 (2022) 266–272 Makhutov N.A./ Structural Integrity Procedia 00 (2019) 000–000

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into account the results ((Makhutov, 2005; Makhutov and Makarenko and et al, 2019; Makhutov and Makarenko and et al, 2010; Makhutov and Makarenko and et al, 2017; Makhutov and Makarenko and et al, 2013; Makhutov and Makarenko and et al, 1999) the equation (3) is offered. [ ] [ ] ∗ ∗ ∗ ∗ − − ∗ ∗ = β σ π α 2 ) (1 1 ( ) sin ( / ) ( , ) (2 ) ( ) ( ) ( ) ( ) ( ) i p ij mi m m m mi p k e e e f r l x y r K k ike k i k i k i k ire (3) ( ) k i m is the harden-ing index in the k-th load half cycle. The remaining parameters are given in (Makhutov, 2005). The relative equivalent stress intensity factor q K was calculated according to the strain intensity value. As an example, Fig. 2 shows the results of numerical calculations by the software package (ANSYS, 2010) for q K in the elastic region of loading depending on the size of the normal tear crack (as the most dangerous for / 2 π β = ). The calculation of the relative equivalent stress intensity factor q K was carried out according to the formula Where Ti m σ σ / mi σ = and e mi e m e Ti / = are the nominal relative stress and elasto-plastic strain at the weld point,

( / )(1 2 ) sin 2 0,5 µ π − ⋅ ∗ ∗ ∗ ∗ i f r l e r

(2 )

∗

2(1 ) 3 µ +

β

∗

K

=

⋅

.

q

ij

Fig. 5 shows a comparison of the numerical and experimental results of determining the relative intensities of elasto-plastic strain on the relative distance near the normal inclined crack contour.

(a) (b) Fig.5. (a) Comparison of the numerical (lines) and experimental (points) results of the relative intensities of elasto-plastic de-formations on the relative distance near the normal tear crack contour; (b) finite element model of a crack.

3. Conclusions The evaluated parameters macro- and micro relief surfaces fracture is inclined cracks, in three-dimensional nominal springy plastic floor strain. The primary mechanisms of the development of the surfaces of the fracture semi elliptic inclined low-cycle surface cracks are determined under joint influence of the normal take-off, transverse and longitude shift.