Issue 78

G. Palomba et alii, Fracture and Structural Integrity, 78 (2026) 233-247; DOI: 10.3221/IGF-ESIS.78.14

compromise the load-bearing capacity. However, a pronounced reduction in ductility is observed, as reflected by the markedly lower uniform elongation and earlier onset of plastic instability. This reduction in strain accommodation capability aligns well with the Digital Image Correlation (DIC) observations discussed previously, which revealed pronounced mechanical heterogeneity and strain localization within the welded gauge region. The limited deformability of the weld metal (WM) and the presence of steep strain gradients near the heat-affected zone (HAZ) interface effectively constrain uniform plastic flow, leading to premature necking and localized damage accumulation. Consequently, the macroscopic tensile response mirrors the underlying spatially non-uniform strain distribution captured by DIC, reaffirming the dominant role of local stiffness variations in dictating global deformation behaviour.

(a)

(b)

Figure 4: Digital Image Correlation strain maps during a tensile test of a non-welded specimen: (a) ε ₓₓ and (b) ε ᵧᵧ .

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