PSI - Issue 28

Wei Song et al. / Procedia Structural Integrity 28 (2020) 200–207 Author name / Structural Integrity Procedia 00 (2020) 000 – 000

203

4

fatigue damage and fatigue lives of test specimens can be obtained from MATLAB. The related multiaxial fatigue analysis procedure has been given in Fig. 4.

(a)

(b)

300 400 500 600 700 800 900 1000

300 400 500 600 700 800 900 1000

90  Out of phase In phase

90  Out of phase In phase

200 Stress amplitude,  a (MPa)

200 Stress amplitude,  a (MPa)

ρ

ρ

 = 0.2mm R=-1,  =1.73 10NiCr3MoV

 =1mm R=-1,  =1.48 10NiCr3MoV

90°

90°

100

100

10 2

10 3

10 4

10 5

10 6

10 2

10 3

10 4

10 5

10 6

Number of cycles to failure, N

Number of cycles to failure, N

(d)

300 400 500 600 700 800 900 1000

(c)

300 400 500 600 700 800 900 1000

ρ

200 Stress amplitude,  a (MPa) 90°

200 Stress amplitude,  a (MPa) 90°

ρ

 =1mm ,  =1.48, OP  =1mm ,  =1.48, IP  =0.2mm ,  =1.73, OP  =0.2mm ,  =1.73, IP  =1mm ,  =1.73, OP  =0.2mm ,  =1.73, OP

 =1mm ,  =1.48, OP  =0.2mm ,  =1.48, OP  =1mm ,  =1.48, IP  =0.2mm ,  =1.48, IP

BM

R=-1

R=-1

10NiCr3MoV

UM

100

100

10 2

10 3

10 4

10 5

10 6

10 2

10 3

10 4

10 5

10 6

Number of cycles to failure, N

Number of cycles to failure, N

Fig. 2 Multiaxial fatigue life comparison of different notch radius of base metal. (a)  =0.2mm for BM; (b)  =1mm for BM; (c) Summary of BM; (d) Summary of BM and UM

Log((r, θ =0))

( r    , r

)

0



=

1

( ) r



=

 eff  max

(

)

,   r

0

=

Stress distribution along notch root

Relative stress gradient

Effective Damage Zone

Notch

L

Log(r)

eff

Fig. 3 Stress gradient and relative stress gradient expressions at notch root.