PSI - Issue 38

Hendrik Bissing et al. / Procedia Structural Integrity 38 (2022) 372–381 Hendrik Bissing, Markus Knobloch, Marion Rauch / Structural Integrity Procedia 00 (2021) 000 – 000

375

4

a) Design of the Incremental Step Test specimen

b) Welded steel sheet

c) Steel sheet with extracted specimens

220.0

[mm]

20.0

60.0

40.0

40.0

60.0

R i 3.5 R o 5.0

Clamping area Transition area Measuring area R ~ 800

Fig. 2. Specimen design and extraction domains for the Incremental Step Tests according to Bissing et al.(2021)

Table 1. Probabilistic parameters of the utilised material in the SLA; Material: S 355 J2 + N; Own test results

Parameter

Dist. *

BM

HAZ

WM

Source

Mean

STD

Mean

STD

Mean

STD

E:

Young’s modulus [GPa] Tensile strength [N/mm²]

LN

202.300

7.830

205.520

3.714

207.043

1.713

f u :

LN

595.9

19.2

607.7

40.1

720.0

76.5

f y :

Yield strength [N/mm²]

LN

397.3

12.8

405.2

26.7

480.0

51.0

K’:

Hardening coefficient [N/mm²] Hardening exponent [-]

LN

818.6

1.3

826.6

13.8

848.2

17.2

n’:

LN

0.139

0.002

0.133

0.011

0.119

0.013

σ f ’:

Fatigue strength coefficient [N/mm²] Fatigue strength exponent [-]

LN

893.8

28.9

911.6

60.1

1079.9

114.7

Own test results

b:

N

-0.082

0.001

-0.080

0.004

-0.075

0.005

ε f ’:

Ductility coefficient [-] Ductility exponent [-]

LN

0.589

0.003

0.585

0.011

0.553

0.020

c:

N

-0.590

0.003

-0.601

0.019

-0.628

0.026

K t :

Stress concentration factor [-]

N

2.650

0.398

FE **

* LN: Lognormal Distribution; N: Normal distribution ** FE Calculations according to Pachoud et al. (2017); Mean and STD of the stress concentration factor K t are not related to the BM

Table 2. Probabilistic densities of parameters used in the CPM

Parameter

Dist.

Mean

STD

Source

C: m: a 0 :

Paris law parameter [(N/mm 3/2 ) m ]

LN

5.860 E-13

3.516 E-13

Paris law parameter [-] Initial crack length [mm]

none

3.000 0.150

[-]

LN LN

0.099

ΔK 0 : Lower boundary Paris law [N/mm 3/2 ] ΔK c : Upper boundary Paris law [N/mm 3/2 ]

140.000 2000.000

56.000

JCSS (2002)

none

none none

c 0 :

Initial crack length 3D [mm]

LN

1 to 10 times a 0

Assumption