PSI - Issue 2_A

F. Berto et al. / Procedia Structural Integrity 2 (2016) 1813–1820 Author name / Structural Integrity Procedia 00 (2016) 000 – 000

1819

R 0 =0.28 mm

0.1 Averaged strain energy density  W [Nmm/mm 3 ] Averaged Strain Energy Density Δ W (Nmm/mm 3 ) Δ W 2.3% Δ W 50% Δ W 97.7% Bare HDG Ps = 97.7 % 1.0 10 4 0.10 1.00 10.00

2 

R 0

R 0

900 fatigue test data

Inverse slope k=1.5

T  W = 3.3

0.192

0.105

2D, failure from the weld toe, R= 0 2D, failure from the weld root, R = 0 Butt welded joints -1 < R < 0.2 3D, -1 < R < 0.67 Hollow section joints, R= 0

P.S. 97.7 %

0.058

Cycles to failure, N

10 5

10 7

10 6

Fig. 5. Fatigue strength of welded joints made of structural steel as a function of the averaged local strain energy density.

S355- R = 0 Scatter Index T W = 3.3  W 50% = 0.105 Nmm/mm

Ps = 2.3%

3 (N = 2 ∙ 10 6 )

R C = 0.28 mm

0.192

k=1.5

0.105

0.058

0.01

1.00E+04

1.00E+05

1.00E+06

1.00E+07

Number of cycles to failure, N

Fig. 6. Fatigue behaviour of uncoated and galvanized welded steel at = 0 as a function of the averaged local strain energy density. Scatter band of 900 experimental data of welded joints made of structural steel is superimposed. Acknowledgements The authors wish to remember with great gratitude Professor Paolo Lazzarin, master of science and life, under whose leadership the research presented in this paper has been planned. Finally they want to express sincere thanks to Ing. Emiliano Guido of Zincherie Valbrenta for his active and valuable collaboration.

References

Berchem, K., Hocking, M. G., 2007. The influence of pre-straining on the high-cycle fatigue performance of two hot-dip galvanised car body steels. Materials Characterization, 58(7), 593 – 602. Bergengren, Y., Melander, A., 1992. An experimental and theoretical study of the fatigue properties of hot- dip-galvanized high-strength sheet