Papers by Keyword: Tailor Welded Blank (TWB)

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Authors: Song Xue, Jie Zhou
Abstract: The strength ratio between two blanks of tailor welded blanks (TWBs) plays an important role in the formability aspect. To study the strength ratio effects on the formability of TWB is significant while more and more TWBs were applied in auto industry. The formability of TWBs square cup was analyzed by numeric simulation technology in the terms of different strength combination TWBs. The results indicate that the formality goes worse dramatically when the strength ratio bigger than 2.0 and the crack located on the higher strength blank side when the crack appeared. The results are applicable.
Authors: R. Safdarian Korouyeh, Hassan Moslemi Naeini, M.J. Torkamany, J. Sabaghzadee
Abstract: Tailor Welded Blanks (TWB) are blanks in which two or more sheets of similar or dissimilar materials, thicknesses, coatings etc. are welded together to form a single sheet before forming. Forming behavior of TWBs is affected by thickness ratio, strength ratio, weld conditions such as weld properties, weld orientation, weld location etc. In this work, Nd:YAG laser welding will be use to weld TWB with different thickness in experimental test. Nd:YAG laser welding parameters such as pulse duration, welding velocity, frequency and peak power will affect formability of TWBs. Taguchis design of experiments methodology is followed to design of experiment and obtain the percentage contribution of factors considered. Erichsen formability test and uniaxial tensile test (ASTM-E8) will be use in experiment setup to compare result of different welding parameters on formability quality of TWBs.
Authors: Shui Sheng Chen, Jian Pin Lin, Jing Liu
Abstract: Tailor welded blanks (TWBs) offer several notable benefits including decreased part weight, reduced manufacturing costs, increased environmental friendliness, and improved dimensional consistency. To take full advantage of these benefits, however, one needs to overcome the reduced formability of TWBs and be able to accurately predict the failure modes depending on the thickness ratio between the thicker and thinner sheets of a tailor welded blank with similar base materials early in the design process. In this paper, we studied the effect of the thickness ratio on the limit dome height of TWBs by using finite element method and experiments, analyzed the effect of TR on the failure mode of TWBs. A concept of the critical thickness ratio was presented to predict the failure modes of TWBs. The results show that the rapture originates on the weld of TWBs when the thickness ratio is less than the critical thickness ratio and on the thinner side when the thickness ratio exceeds the critical thickness ratio.
Authors: Chi Ping Lai, Luen Chow Chan, Chi Loong Chow
Abstract: This paper aims to study the effect of stress relieving on Limit Dome Height (LDH) of Ti-TWBs at elevated temperatures. This is achieved by developing a newly constructed heating system. The elevated temperature of the system can be varied and monitored by a separately control panel. All Ti-TWBs were prepared and used to examine the LDHs under elevated temperatures. Selected specimens were heat-treated at 600°C within an hour before being formed by HILLE machine. Meanwhile, the temperature of tool heating system was also adjusted from room temperature to 550°C. Specified tests were carried out to examine the stress relieving effects of Ti-TWBs on the LDHs with the temperature control panel. In addition, investigations were carried out to ascertain whether the elevated temperatures of the critical tooling components, i.e. the die and the blank holder, could result in any significant effects on LDHs of Ti-TWBs. The findings show that LDHs of Ti-TWBs can be improved by stress relieving. The stress relieving condition can be obtained by nearly isothermal forming of specimens at a range of 550°C to 600°C.
Authors: Chi Ho Cheng, Luen Chow Chan
Abstract: Strong interest in producing ultra-light-weight, high corrosion-resistant, heat-proof and tougher advanced products has prompted potential development of titanium tailor-welded blanks (Ti-TWBs) to construct the critical parts of structures and panels in automotive applications and some other advanced industries. However, the capability to predict the forming behavior of the stamped TWBs without failure lags far behind the manufacturing technology. It is proven that the ductility for most of the titanium alloy sheets can be significantly improved at elevated temperatures. Nevertheless, such study of stress-strain behavior on the weldment of Ti-TWBs has not been fully investigated. This paper aims to analyze the forming behavior of the Ti-TWBs at different elevated temperatures using a finite element analysis. The distinctive mechanical properties of the base metals and weldment for the forming simulations will be acquired experimentally. Finally, it is found that, due to the increase of ductility, the forming behavior of Ti-TWBs will not be considerably improved unless the forming temperature is kept between 500oC and 600oC.
Authors: Wei Liu, Xiao Guang Wang, Ming Zhe Li
Abstract: Multi-point forming (MPF) is a flexible manufacturing technique, which is made up of a set of adjustable base elements controlled by MPF-CAD/CAM software. It uses discrete punches to express a continuous 3-D surface, by which the work piece’s surface under manufacturing is formed. In this paper, to investigate the feasibility of the multi-point forming for the tailor-welded blank ( TWB ), the explicit finite element model for TWB in MPF is established, then spherical surface TWB is selected as an example to analyse reason for generation of weld joint offset defect, and finally method to suppress generation of defect is proposed. The results show that in MPF for spherical surface part, weld joint removes to thick blank direction in zone of expanding and suspending, but to think blank in zone of blank holder; weld joint offset can be controlled effectively by adopting stepped blank holder and applying proper blank holder force .
Authors: António José Baptista, Dulce Maria Rodrigues, Luís Filipe Menezes
Abstract: In new car production, an innovative method to produce strong and light panels consists in applying Tailor Welded Blanks (TWBs) in the body-in-white base structure. Since the fusion welding processes can induce significant changes in the material properties of the base materials, an important question is whether the weld bead has a significant influence on the overall behaviour of the welded blanks. In this work, some preliminary conclusions on this subject were achieved based on results of the numerical simulation of simple mechanical tests: tensile, shear and simple bending. The numerical simulations were performed with a fully implicit finite element program (DD3IMP). The results obtained show that for a slight mismatch of properties between the weld and the base materials, no important influence of the weld in the TWBs behaviour is noticed. However, a significant strength reduction can be observed for strong undermatch conditions (lower mechanical properties in the weld) even when the weld bead is very narrow.
Authors: R. Safdarian Korouyeh, Hassan Moslemi Naeini, Golam Hosein Liaghat, M.M. Kasaei
Abstract: Weld line movement is one of the important parameters in Tailor Welded Blanks (TWB) forming. Weld line movement is important from some aspects: First, weld line position in the final part is so important because TWB part will be assembled with other parts and weld line movement can influence on assembling. Second, weld line movement which often is towardthe stronger (thicker) metal cause necking and fracture in weaker (thinner) metal. A forming criterion for tailor welded blank will be presented based on the analytical model in this research. This criterion suggests Limit Strength Ratio (LSR) and Limit Thickness Ratio (LTR) for forming limit of TWB.When thickness ratio or strength ratio in tailor welded blank is greater than LTR or LSR, weld line movement will be increased and cause forming decrease. Some simulation tests are done for correction investigation of this theoretical model.
Authors: Hao Bin Tian, Zhen Lei Li, Xiao Feng Deng, Xian Ping Liu
Abstract: Tailor welded blanks (TWBs) get popular used in the automobile for the light-weighting, and the assessments for TWBs formability are more and more important owing to the TWBs with different thicknesses. In this paper, based on the tensile test and low carbon high strength steel (ZStE220P), the influences of seam location and the length of sample on the elongation are studied, and the results shows that the location of seam has greater effect on the formability of TWBs and elongation is getting decreased with the seam shifting to the thinner part.
Authors: Hao Bin Tian, Xiao Hang Liu, Jian Ping Lin, L.M. Smith
Abstract: Tailor welded blanks had been widely used in automobile industries. In this paper, the formability of tailor-welded blanks with curved seams had been studied in experiments, and compared with that of tailor-welded blanks with straight seams. For tailor welded blanks with curved welded seams, the effects of thickness ratio on the limited forming height are the same under various welded seam shape, and the limited forming heights are decreased and then increased with the increase of thickness ratio, which different to that obtained from tailor-welded blanks with straight seam. The reasons that the shapes of welded seam how to influence the formability of tailor welded blank are deduced in the paper. Results show that the shape of the welded seam can change the blank’s deformation condition, which one of the main factors of determining the sheets formability.
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