Full Field Strain Measurement of Resistant Spot Welds Using 3D Image Correlation Systems

This paper describes local strain measurements of electrical resistance spot welds for three sheet stack-ups of Dual Phase (DP600) and Mild steel under quasi-static tensile loading. The experiments were designed to measure local strain distributions at the vicinity of the spot welds using a modified tensile-shear specimen geometry that allows a strain measurement system to access such area. The electrode tip type used was B-nose, and surface indentation levels were 30% and 50% of the sheet thickness. Local strains at critical locations in resistance spot welds were measured using non-contact 3D image correlation systems (ARAMIS) during quasi-static tension tests. The measured local strains were also compared with results offered by a finite element analysis.