PSI - Issue 50

S.V. Panin et al. / Procedia Structural Integrity 50 (2023) 220–227 S.V. Panin et al. / Structural Integrity Procedia 00 (2023) 000 – 000

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were fabricated. The results of the shear tests of the lap welded joints are shown in Fig. 1, a and in Table 2. Also, thicknesses of the joints were evaluated before and after USW (Fig. 1, b), the results of their analysis are presented below. Table 1. The summarized factors and their levels in the USW process according to the Taguchi table of the L9 format for the three factor experiment.n example of a table. Experiment number Level / Factor USW process duration, ms Compression force, atm

Compression (holding) duration after USW, ms

1 2 3 4 5 6 7 8 9

1 / 800 1 / 800 1 / 800

1 / 500 2 / 1000 3/ 1500 1 / 500 2 / 1000 3 / 1500 1 / 500 2 / 1000 3 / 1500

1 / 2 2 / 3 3 / 4 2 / 3 3 / 4 1 / 2 3 / 4 1 / 2 2 / 3

2 / 1.000 2 / 1.000 2 / 1.000 3 / 1.200 3 / 1.200 3 / 1.200

Fig. 1. (a) The stress – strain diagrams for the welded samples and (b) changes in the thickness of the lap joints before and after USW.

Table 2. The thicknesses and the mechanical properties of the welded joints. Experiment number Thickness after USW, mm Elongation at break (  ),%

Shear strength ( ℎ ), MPa 68.0

Work of fracture ( A ), N · m

1 2 3 4 5 6 7 8 9

0.40 0.35 0.26 0.38 0.37 0.54 0.50 0.87 0.62

3.5 8.5 1.2 6.6 2.7

156.2 424.7

94.4 29.1 92.6 55.1 96.5 94.1 90.7 95.9

51.7

284.3

95.6

10.2 12.5

558.6 694.4 213.3 950.0

5.3

16.0