Papers by Keyword: Tailor Welded Blank (TWB)

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.

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.

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.

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.

Abstract: The stamping process of the tailor welded blank(TWB) was simulated by the software of DYNAFORM. The finite element model of a boxy part was founded, and the forming of different thickness and properties of the material was studied. Meanwhile, the influence of weld seam on forming result was analyzed. The results show that the weld seam model which founded by real properties can describe the plastic deformation and strain distribution more exactly in the forming process.

Abstract: Mismatch is one of the main defects of tailor welded blanks(TWB), and leveling technology is a new method which can solve this problem. The structures, force analysis and flange morphology of the leveling mechanism are studied in this paper, and a three-dimensional prototype is designed. The results have practical significance for improving welding quality of TWB.

Abstract: With more and more attention to the technology of tailor welded blanks (TWBs), it is vital to study the springback of TWBs. In this paper, the springback law of parallel and perpendicular to the weld of TWBs hyperboloid shallow shell affected by blank holder force, punch string height, and the difference of blank thickness was researched by finite element software. The results show that: by means of drawing and trimming, the springback of TWBs can be reduced, and the curvature of TWBs is less parallel to the weld, but the curvature is larger perpendicular to the weld. The effect of blank holder force on the trimming springback is relatively small in the range of experimental date. With the punch string height increasing, the drawing and the trimming springback are both increased firstly and then gradually decreased perpendicular to the weld, and the drawing and the trimming springback are both decreased parallel to the welding. And perpendicular to the weld, with the increase of the quadratic difference of thickness, the drawing springback of the thinner side is gradully decreased, and the drawing springback of the thicker side is gradually increased, after trimming, the springback of the thinner and the thicker side are both less than the drawing springback, and parallel to the weld, the drawing and the trimming springback are decreased firstly and then increased with the increase of the quadratic difference of thickness.

Abstract: In this study, the springback law of generatrix direction, circumferential direction of tailor welded blanks (TWBs) cylinder shallow shell impact from blank holder force, punch profile radius and sheet thickness was researched by finite element analysis, which was compared with non-welded blanks. The results show that: in the circumferential direction, with the increase of blank holder force, the trimming springback of the tailor welded blank of the thickness combination of 1.2mm and 0.8mm (TWB1208) is decreased firstly and then increased, which is larger than that of the non-welded blanks of 0.8mm and 1.2mm. With the increase of punch profile radius, the drawing and the trimming springback of TWB1208 are both increased, and after trimming, the both springback are greater than that of the non-welded blanks. With the increase of the quadratic difference of thickness, TWB1208, TWB1612 and TWB1608, the drawing springback is decreased, and the trimming springback is gradually increased. In the generatrix direction, when blank holder force is less, the distortion deformation of TWBs is serious, and after the trimming, it is decreased according to the increasing blank holder force. With the increase of punch profile radius, the distortion deformation is larger. The greater the difference of thickness is, the more serious the distortion deformation is.

Abstract: A simulation model for the filling of a tubular cavity during water assisted injection molding is proposed. The polymer melt and water are assumed to be incompressible and to follow a Hele-Shaw fluid behavior. The finite element/finite difference/control volume methods are adopted for numerical simulation of the melt front, pressure at injection location variation, water thickness fraction and bulk temperature about a curved pipe, the simulation results have good agreement with the results presented in the former experiment. In comparison with the simulation result of gas-assisted injection molding, water assisted injection molding can give parts with thinner and more uniform walls and more rapid cooling.

Abstract: Magnesium alloy tailor-welded blanks(MTWBs) of AZ31 and AZ80 sheet had been manufactured by gas tungsten arc welded(GTAW), which the thickness were 0.8mm. The welding properties of Magnesium alloy sheet had been analyzed, and the technology parameters of GTAW were determined by experiment study, which was that welding thread being Φ2.0mm, welding electricity 50A, welding voltage 9V, welding rate 12—13cm/min. The research results presented that the grain in welded seam was isometric crystal, and the grains were branching crystal in heat-affected zone (HAZ). For MTWBs of AZ31and AZ80 sheet which the thickness was 0.8mm, the forming parameters were that the forming temperature of AZ31 being 190-220°C, and forming temperature of AZ80 being 310°C-350°C, and the temperature of tools is 180°C~200°C.