PSI - Issue 57

Rando Tungga Dewa et al. / Procedia Structural Integrity 57 (2024) 762–771 Dewa et al./ Structural Integrity Procedia 00 (2019) 000 – 000

765

4

̇ = ( )

(1) Where ̇ is strain rate, N f is fatigue life in terms of number of cycle to failure, A and b are constants describing the regression fit (intercept and slope), respectively.

10 -2

10 -3 Strain rate (s -1 )

3.02996

= 6.75E-14 (N f )

10 -4

2000

4000

6000 8000 10000

Cycles to failure

Fig. 3. The function of LCF life with the variation of strain rates for Alloy 617.

0,332

10 2

0,33

0,328

0,326

10 1

0,324

0,322 Plastic strain (%)

Time to failure (hr)

0,32

-0.01096

-0.7228

 p = 0.30433 ( )

t r = 0.1075 ( )

0,318

10 0

10 -4

10 -3

10 -2

10 -1

10 -4

10 -3

10 -2

10 -1

Strain rate (s -1 )

Strain rate (s -1 )

(a)

(b)

Fig. 4. The plot of diagrams: (a) Plastic strain versus strain rates, and (b) Time to failures with strain rates function.

In order to provide a better understanding in damage parameter, fatigue life function is then plotted in Fig. 4, with plastic strain and time to failure spent until fracture. This relationship is described in the following equation: