Numerical and Experimental Analysis of the Behavior of Tailor Welded Blanks to the Uniaxial Tensile Test

In laser welding of Tailor Welded Blank (TWB), the melt zone (MZ) and heat-affected zone (HAZ) are very narrow, which makes it difficult to measure the mechanical properties of this region. This work sought to correlate the results of experimental uniaxial tensile tests with TWBs in which the weld line had different orientations, to numerical simulations. We worked with the Abaqus® software, considering the properties of the weld line, obtained with the Rule of Mixtures. TWB composed of interstitial-free steels of different mechanical properties was used, which led to the union of three different zones (two base materials and the welded region). The mechanical properties of the elastic and plastic regime of the tensile test were taken into account. It was found that weld makes a difference in the results, but for this to be really perceived, it is necessary to refine the mesh in the region, demanding more processing time. Whether or not the weld is considered, as long as it is qualified, rupture tends to occur in the material with the lowest mechanical resistance. The weld has greater mechanical strength and relative ductility, acting as a stress concentrator and changing the fracture direction of the TWB under tensile stress. The Rule of mixtures proved to be effective for representing the weld and the numerical model represented by the finite element method, with the imposed boundary conditions and simplification of the material as isotropic, proved to be valid with consistent results in relation to rupture load and elongation.