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Tailor welded blanks offer an excellent opportunity to reduce manufacturing costs, decrease vehicle weight, and improve the quality of sheet metal stampings. However, tearing near the weld seam is a concern in Tailor Welded Blanks due to material changes in the fusion and heat affected zones of the weld. Therefore, data is required such as the potential strain of the material in these areas to use in the process design. For example, Cao and Kinsey proposed a modification to the deep drawing process where segmented dies with local adaptive controllers clamp adjacent to the weld line during the forming operation thereby reducing the strain in the material near the weld seam and in turn the concern of tearing failure. In order to aid in the design process for this modification, an understanding of the effects of the welding process on material changes near the weld seam is essential.

Minimization of part variation has been a challenging topic for both researchers and engineers. Variations in final stamping parts could come from numerous sources such as incoming material, lubricant, processing parameters, environment, automation, etc. Identifying the cause of the variations is not only time consuming, but also a continuously changing process. In this paper, experiments are reviewed which were conducted to examine the feasibility of implementing closed-loop process control to reduce dimensional variations on an in-production 3D part. Specifically, the effects of punch force (PF) and binder force (BF) on part dimensions are studied. For our particular application, proper control of both PF and BF is necessary to control the dimensional variations of the part.

In order to effectively design sheet metal components using numerical simulations, an accurate means to predict tearing concerns is necessary. Currently, a strain based failure criterion is used to predict this type of failure in the automotive and aerospace industries. However, due to the strain path dependence of the strain based Forming Limit Diagram, accurate prediction is only possible for forming cases which possess a single linear strain path. Alternatively, a stress based failure criterion has been proposed and demonstrated analytically, experimentally in tube forming, and through numerical simulations. In this paper, further support for the stress based failure criterion is provided by demonstrating that the saturation of the stress level during plastic deformation is not the cause of the convergence of various strain based Forming Limit Curves to a single curve in stress space.

Tailor welded blanks (TWBs) offer an excellent opportunity to reduce manufacturing costs, decrease vehicle weight, and improve the quality of auto body stampings. However, tearing near the weld line and wrinkling in the die addendum often occurs when a traditional forming process is used to fabricate this type of blank. Cao and Kinsey [1] proposed a modification to the stamping process where a mechanism would clamp on the weld line during the deep drawing process to improve the formability of TWBs. Critical to the success of this proposed modification is the ability of the clamping mechanism to perform its intended function and avoid creating adverse effects in the forming process. In this paper, numerical simulations verify the ability of the clamping mechanism to hold the weld line in place during forming and not severely deform the blank in the area of the clamping mechanism.

Tailor welded blanks offer a unique opportunity to reduce manufacturing costs, decrease vehicle weight, and improve the quality of stampings through the consolidation of multiple formed, then welded, parts into a single stamping. However, tearing near the weld line often occurs in this type of blank when formed with a traditional deep drawing process. Therefore, some adaptation to the existing sheet metal forming process must be developed in order to reap the numerous benefits available from tailor welded blanks. In this paper, numerical simulation are presented for a newly contrived tailor welded blank forming process where several hydraulic mechanisms apply distinct clamping forces along the weld line during forming. Excellent results demonstrate the effectiveness of the proposed method.