Issue 45

L. Zou et alii, Frattura ed Integrità Strutturale, 45 (2018) 53-66; DOI: 10.3221/IGF-ESIS.45.05 62 equivalent structural stress range is fitted by using least square method as Mean1 in Fig. 10. Mean of the master S-N curve defined in Tab. 1 is shown as Mean2 in Fig. 10. Goodness-of-fit statistics of Master S-N curve by using Eq.SS Range is shown in Tab.10. For more detailed about the definition of SSE , R-square , Adjusted R-square and RMSE , please see reference [26]. Figure 10: Master S-N curve based on Eq. SS Range. Material type Welding method Thickness ( mm ) Ratio Loading type Joint type Equivalent structural stress range( MPa ) Life cycles 5083 H11 MIG 10 0.1 4B TJ:p 187.6994 29250 5083 H11 MIG 10 0.1 4B TJ:p 160.8852 55000 AlMg4MnCr GMAW 2.5 0.1 T LJ_SS:p 154.7135 20540 AlMg4MnCr GMAW 2.5 0.1 T LJ_SS:p 85.0924 121730 AlMgSi1 (6082) TIG 3 0 T LJ_DS:p 294.1392 13250 AlMgSi1 (6082) TIG 3 0 T LJ_DS:p 159.7613 85920 NP5/6 Manual Arc 4.76 0 T SJ_DS:p 154.9481 90000 HP30 Manual Arc 4.76 0 T SJ_DS:p 116.2111 188000 5A06+5083 MIG 10 0.1 3B T 81.19 452100 5A06+5A06 MIG 16 0.1 3B T 129.69 272900 Table 9 : Fatigue data of aluminum alloy welded joints. Mean value SSE 0.4389 R-square 0.7929 Adjusted R-square 0.7901 RMSE 0.0770 Table 10 : Goodness-of-fit statistics of master S-N curve by using Eq.SS range. Expression of the mean S-N curve of aluminum alloy welded joint based on the Eq.SS range obtained in the experiment is shown as the following Eqn.(10).