PSI - Issue 47

4

A. Califano et al. / Procedia Structural Integrity 47 (2023) 842–848 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 2. (a) Schematization of a specimen obtained from the single lap joint and equipped with two strain-gauges: S1 and S2. (b) Actual equipped specimen (1B1). 3. Results and Discussion The results coming from the tensile tests were reported in this section. As a single lap joint, when subjected to a tensile load, tends to bend in correspondence of the overlapping region, as qualitatively shown in Figure 3a, the measured strains are mainly compressive. Examples of the load/strain curves are reported in Figure 3b for the specimen 1C1, showing, on the x-axis, the absolute value of the measured compressive strains. It can be noticed that the curve obtained from the strains measured by S1 (blue curve) and the one obtained from the strains measured by S2 (orange curve) are quite in agreement, meaning that the deformations on the two sides of the welding were similar each other.

Fig. 3. (a) Schematization of the qualitative deformed shape of a single-lap joint subjected to tensile load. (b) Load/Strain curves for the specimen 1C1 obtained through the strain-gauge S1 (blue curve) and the strain-gauge S2 (orange curve).

A comparison of the load/strain curves obtained through S1 for all the specimens is reported in Figure 4a, while the same curves obtained through S2 are reported in Figure 4b. Analysing Figure 4a, it can be noticed that the deformations measured on the same side as that of the welding bead are in agreement and similar to each other. However, this behaviour is not true for the deformations measured on the opposite side, as the curves in Figure 4b clearly diverge. This is associated to the varying characteristics of both the welding and the fracture surfaces, for the six specimens, which are related to the different combinations of the welding parameters. As a matter of fact, the