PSI - Issue 75

Luca Vecchiato et al. / Procedia Structural Integrity 75 (2025) 602–608 Luca Vecchiato et al. / Structural Integrity Procedia (2025)

606

5

d min =0.8 mm

Δσ =1MPa Δτ =1MPa

X

Y

Fig. 2. FE model.

The experimental results were compared with the PSM-based fatigue design scatter band corresponding to an inverse slope k = 6.5 (Figure 4), the local biaxiality ratio λ (Eq. (4)) at the weld toe being greater than zero because of the presence of mode III. As shown in Figure 4, experimental data demonstrates good agreement with the PSM-based design scatter band, confirming the reliability of the PSM method under both CA and VA loading.

1000

Δσ A,50% = 123 MPa N A = 2 ∙10 6 cycles Scatter Index (2.3%-97.7%): T σ = 166/92 = 1.80 Slopek = 6.5

PSM design scatter band for aluminium joints, λ > 0

92 166 123

D 2.3% = 7.02 D 50% = 1.00 D 97.7% = 0.15

100

Δσ eq,peak [MPa]

Runout

B+T, φ0 , CA B+T, φ90 , CA B+T, φ0 , VA B+T, φ90 , VA

17 CA data

13 VA data

10

N A

1E+4

1E+5

1E+6

1E+7

N 0 [Cycles]

Fig. 4. Data from Kueppers and Sonsino (2006) compared with the PSM design scatter band for aluminium welded joints under multiaxial loads.