Effect of weld conditions on the deformation behaviour of Tailor Welded Blanks (TWB)

Abstract

The critical issue during finite element analysis of tailor welded blank is the handling of the weld region either the weld may be treated just as a weld line (without imposing mechanical properties) or as a weld zone (by imposing separate mechanical properties to the weld zone). The formability of TWB will be affected not only by the weld characteristics but also by the relative mechanical properties of the weld zone and the base metal. The above effects will be discussed in this paper by considering the tensile and Limiting Dome Height (LDH) testing of the TWB. Tensile testing will be modeled using standard tensile specimen. In LDH simulations, samples deforming near plane strain and balanced biaxial stretching will be modeled. Load-progression behavior will be monitored. Throughout this study, simulations will be performed by finite element analysis. By analyzing the simulation results, the specific conditions where the weld zone assumption should be followed will be identified. It is found from the analysis that modeling weld region as weld line is not accurate for all the weld conditions. Also the domain of weld conditions wherein weld line assumption breaks down depends on the deformation mode or part shape.