PSI - Issue 57

Magnus Andersson et al. / Procedia Structural Integrity 57 (2024) 307–315 M. Andersson et al. / Structural Integrity Procedia 00 (2023) 000–000

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Fig. 9. (a) A-stay; (b) the weld cross section: double sided i2a5.

Fig. 10. (a) Normalized life; (b) structural stress for the dominating load case (vertical force).

5.2. Comparing SFM with the E ff ective Notch Method in a weld in an autonomous hauler frame

The model of the frame and the 33 load positions may be seen in Fig. 4. There are 6x33 = 198 unit load cases (three forces and three moments in each load position). Fig. 11 shows the weld position and cross section. The normal stress in local z ′ -direction is extracted along the local x ′ axis (at v ref = 45 ◦ ) for each of the unit load cases. The linearized stress is stored in σ FEA , i ( v ref ) for each unit load case i , see section 3.1. For this weld position the dominating stress is parallel to the weld (i. e. local y ′ -direction). This is common for a single sided fillet weld. Since the e ff ective notch method takes the complete stress tensor into account, the life prediction will be conservative. In Fig. 12(a) the structural stress time history for one of the test track cases is shown. Each test track case has one part where the machine is loaded and one part where it is empty. As can be seen the stress in the weld is clearly higher when the machine is loaded. In Fig. 12(b) the resulting normalized fatigue life for di ff erent cases is shown. The normalization is