Abstract Scope |
Tensile testing is an important method to destructively test materials. Such tests can yield numerous materials and mechanical properties if properly done. However, the tensile test is not immune to its own short comings. Standardized tensile testing works well for homogenous materials, where properties across the gauge section should be uniform. This is not the case with cross weld tensile testing (CWTT). Weld metal and base metal properties are typically closely matched, but not identical. The base metal heat affected zone (HAZ) is also a concern, as the heat from welding can cause numerous reactions upon heating and cooling, further altering
materials properties of the parent material. This is even more complicated in the case of dissimilar metal welds (DMWs), where weld and base metal properties cannot be uniform. According to AWS B4.0:2016, extensometer use is not required for CWTT. Using digital image correlation (DIC), displacements of unique regions within the welded joint can be obtained during CWTT, opening new avenues to testing of matching and dissimilar metal welds and achieving better understanding of non-uniform materials properties across the welded joint. In this paper, the DIC aided cross weld tensile testing will be evaluated for its accuracy at various length scales. Comparing digital DIC extensometers with traditional physical extensometer data reveals DIC can detect the displacement fields necessary to distinguish materials properties of the macro regions of the weldments. Additionally, the ability to generate digital extensometers in the DIC software frees the physical attachment requirement, allowing more flexibility and better data acquisition with complex sample geometries. |