The Research of Forming Process Parameters Influence on the Square Cup of TWBs’ Weld-Line Movement

2014 ◽  
Vol 644-650 ◽  
pp. 4835-4839
Author(s):  
Yong Gan ◽  
Han Chao Wang ◽  
Ying Ying Guo
Keyword(s):  
Weld Line ◽  
Base Material ◽  
Thickness Ratio ◽  
Strength Ratio ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Weld Line Movement ◽  
Lubrication Conditions ◽  
Line Movement

The forming process of the square cup of TWBs is studied through the numerical simulation by Dynaform, and combined with orthogonal test, analyzed the thickness ratio, strength ratio, weld-line position, total blank-holder force, the thinner side’s blank-holder rate and the friction coefficient’s relations with the square cup of TWBs’ weld-line movement during the stamping process, and using the BP neural network toolbox model to forecast the weld-line movement in the process of forming. Studies show that regardless of the thickness ratio impact on the bottom of the square cup or on the flange, weld-line movements are at the maximum, the strength ratio is the second. The smaller proportion of the thinner side of the base material, the lower weld-line movement is. Selecting the suitable thinner side and thicker side’s blank-holder, and the reasonable lubrication conditions can control the value of the weld-line movement.

Theoretical and experimental investigation of deep drawing of tailor-welded IF steel blanks with non-uniform blank holder forces

2016 ◽  
Vol 231 (2) ◽  
pp. 286-300 ◽  
Author(s):  
Mohammad Hossein Asadian-Ardakani ◽  
Mohammad Reza Morovvati ◽  
Mohammad Javad Mirnia ◽  
Bijan Mollaei Dariani
Keyword(s):  
Deep Drawing ◽  
Weld Line ◽  
Body Parts ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Tension Distribution ◽  
Strip Drawing ◽  
Parts Manufacturing ◽  
Weld Line Movement ◽  
Line Movement

Tailor-welded blank is one of the promising technologies in the application of lightweight materials for auto body parts manufacturing. The material discontinuity across the weld line results in an inhomogeneous deformation and weld line displacement. In this study, a two-dimensional analytical model is proposed to predict the tension distribution along the cross section. An energy method is used to calculate the restraining force due to bending, sliding, and unbending phenomena on the die and punch radii. To control the weld line movement, a blank holder force control strategy is proposed to achieve force equilibrium at the bottom of the part across the weld line. Finite element simulations are performed to study the effect of die and punch radii, friction coefficient, thickness ratio, and blank holder forces on the weld line displacement in strip drawing process. Under a uniform blank holder force, the weld line moves toward the thicker/stronger side implying a higher blank holder force is required for the thinner/weaker side. The results show that the weld line displacement can be controlled by an appropriate blank holder force adjustment. In order to control the weld line movement in square cup deep drawing, blank holder force on the thinner side is increased and its influences on the deformation process are investigated. Comparisons of material draw-in, weld line movement, and forming force show a good agreement between the theoretical, numerical, and experimental results.

Effect of Variable Blank Holder Force on the Springback and Weld-Line Movement During Draw-Bending of Tailor Welded Blanks

2015 ◽  
Author(s):  
Bishoy M. Dawood ◽  
Mostafa Shazly ◽  
Abdalla S. Wifi ◽  
Alaa El-Mokadem
Keyword(s):  
Finite Element ◽  
Weld Line ◽  
Bench Mark ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Tailor Welded Blanks ◽  
Variable Blank Holder Force ◽  
Draw Bending ◽  
Weld Line Movement ◽  
Line Movement

Tailor welded blanks (TWBs) manufactured by drawing processes suffer from two major defects; weld-line movement (WLM) and springback. These defects can be reduced by using a counterpunch or controlling the value of the blank holder force and its scheme. This work presents a finite element analysis of the effect of variable blank holder force (VBHF) on springback and WLM of bench mark problem of draw-bending process of a TWB. The proposed VBHF scheme is developed based on the reaction forces predicted in a finite element model for artificially clamped weld-line case. The results obtained by applying VBHF are compared with those obtained using a counterpunch. The use of counterpunch is found to eliminate Vertical WLM in all the considered cases. Whereas side WLM using VBHF is found to be less than that obtained using counterpunch. When compared to the counterpunch technique, the springback values are found to be improved by applying the VBHF schemes.

Investigation of Weld Line Movement in Tailor Welded Blank Forming

2012 ◽  
Vol 445 ◽  
pp. 39-44 ◽  
Author(s):  
R. Safdarian Korouyeh ◽  
Hassan Moslemi Naeini ◽  
Golam Hosein Liaghat ◽  
M.M. Kasaei
Keyword(s):  
Weld Line ◽  
Thickness Ratio ◽  
Forming Limit ◽  
Strength Ratio ◽  
Line Position ◽  
Tailor Welded Blanks ◽  
Limit Strength ◽  
Tailor Welded Blank ◽  
Weld Line Movement ◽  
Line Movement

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.

Comparison of Analytical Model to Experimental Results and Numerical Simulations for Tailor Welded Blank Forming

2004 ◽  
Author(s):  
Matt Bravar ◽  
Brad Kinsey ◽  
Neil Krishnan
Keyword(s):  
Numerical Simulations ◽  
Analytical Model ◽  
Weld Line ◽  
Experimental Results ◽  
Forming Process ◽  
Tailor Welded Blanks ◽  
Industrial Utilization ◽  
Initial Placement ◽  
Weld Line Movement ◽  
Line Movement

Tailor Welded Blanks offer several notable benefits including decreased part weight, reduced manufacturing costs, and improved dimensional consistency. However the reduced formability and other characteristics of the forming process associated with TWBs has limited the industrial utilization of this blank type. One concern with TWB forming is that weld line movement occurs which alters the final location of the various materials in the TWB combination. In this paper, an analytical model to predict the initial weld line placement necessary to satisfy the desired, final weld line location is presented. Good agreement between the model, experimental results, and numerical simulations with respect to weld line movement and initial placement was obtained for a symmetric, steel TWB case and a non-symmetric, Aluminum TWB case.

Maximum Bulge Height and Weld Line Displacement in Hydroforming of Tailor Welded Blanks

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
A. Kumar ◽  
V. Gautam ◽  
D. R. Kumar
Keyword(s):  
Weld Line ◽  
Thickness Ratio ◽  
Dome Height ◽  
Interstitial Free ◽  
Tailor Welded Blanks ◽  
Tailor Welded Blank ◽  
Hydraulic Bulging ◽  
Weld Line Movement ◽  
Bulge Height ◽  
Line Movement

Tailor welded blank (TWB) has many advantages over a traditional blank for manufacturing automobile sheet metal components, such as significant flexibility in product design, higher structural stiffness, and crash behavior. However, lower formability and weld line movement are some of the problems associated with forming of TWBs. Hydroforming is a potential technique to enhance formability. In this work, the effect of thickness ratio on maximum dome height and weld line movement in hydraulic bulging of laser welded interstitial-free (IF) steel blanks of different thickness combinations has been predicted using finite element (FE) simulations. The results are also validated with hydraulic bulging experiments on TWBs. It has been found that with increase in thickness ratio, the maximum bulge height decreased and weld line displacement toward thicker side increased. These results have been used to relocate the weld line toward the thinner side in the initial blanks and achieve a more uniform bulge profile of the dome. The peak pressure to achieve maximum safe dome height and percentage thinning has also been found out. The results showed huge improvement in uniformity of bulge profile with little reduction in dome height.

Influence Principles of Linear-Weld-Line Tailor-Weld Blanks’ Formability with Different Thickness of Base Metals

2014 ◽  
Vol 556-562 ◽  
pp. 507-510
Author(s):  
Yong Gan ◽  
Han Chao Wang
Keyword(s):  
Base Metal ◽  
Great Influence ◽  
Weld Line ◽  
Dome Height ◽  
Forming Process ◽  
Mathematical Expressions ◽  
The Difference ◽  
Weld Line Movement ◽  
Different Thickness ◽  
Line Movement

Discussing the influence between the linear-weld-line TWBs’ different thickness of base metal and the formability of sheet by Dynaform FEM simulations technology and Dome test. Meanwhile, the correlation with the difference thickness of base metal and the limit doming height, weld-line movement are proposed, we find that both sides of the TWBs’ thickness have a great influence on the forming process. Then, the mathematical expressions are proposed between the changing thickness of base metal and limiting dome height, weld-line movement by using the genetic algorithm to fit the simulations’ data, which provide an evidence for production in theory.

Study on Formability of Tailor-Welded Blank Based on Sheet Metal Matching

2010 ◽  
Vol 139-141 ◽  
pp. 618-621
Author(s):  
Jin Lun Wang ◽  
Feng Chong Lan ◽  
Ji Qing Chen
Keyword(s):  
Mechanical Properties ◽  
Sheet Metal ◽  
Weld Line ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Shaped Part ◽  
Single Sheet ◽  
Tailor Welded Blank ◽  
Forming Defects

As tailor-welded blank having two or more sheet metal welded together, with different mechanical properties, coating and thicknesses, its yield strength and tensile strength are higher, but hardening exponent and elongation are lower than a single sheet. The different mechanical properties of substrates and weld movement have significant effects on TWB’s formability, different materials or thicknesses easily lead to uneven deformation and forming defects such as cracking, wrinkle and springback. This paper takes tailor-welded box-shaped part for example; the forming process and weld movement were simulated and analyzed. In this process, the weld type was ignored, only considering the weld-line position, using segmented blank holder to control the size of the blank holder force on both sides respectively. Three cases of sheet metal matching were carried out including: different thicknesses with same material, same thickness with different materials, and different thicknesses with different materials. Finally, some meaningful results were obtained.

Research about Warm-Hot Forming Process Control of LTWB Auto B-Pillar

2012 ◽  
Vol 472-475 ◽  
pp. 3078-3082
Author(s):  
Yu Qin Guo ◽  
Xin Yang ◽  
Juan Juan Han ◽  
Wei Chen ◽  
Meng Zhao
Keyword(s):  
Process Control ◽  
Process Parameters ◽  
Industrial Production ◽  
Weld Line ◽  
Compensation Method ◽  
Hot Forming ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
The Times

In recent years, with the trend of auto body lightweight, more and more auto manufacturers pay attention to warm-hot forming of laser tailor weld blank (LTWB). In this article, choosing Audi Q5 B-pillar as the study object provided by Benchmark 2008 and using the stamping specific software Autoform, the effects of blank holder force (BHF) and drawbead on the formability of B-pillar are studied in different forming tempreture and put forward the reverse compensation method to control the weld line offset and the reverse compensation quantity is quantized, which has great significance to direct the industrial production, determine the process parameters of warm-hot forming and reduce the times of trying dies.

Numerical Simulation and Experimental Study on the Weld-Line Movement of Tailor-Welded Blank

2010 ◽  
Vol 97-101 ◽  
pp. 357-360 ◽  
Author(s):  
Xiu Li Hu ◽  
Hao Zhao ◽  
Zhong Wen Xing
Keyword(s):  
Numerical Simulation ◽  
Influence Factors ◽  
Weld Line ◽  
Forming Process ◽  
Forming Technology ◽  
Element Simulation ◽  
Tailor Welded Blank ◽  
Weld Line Movement ◽  
Line Movement ◽  
Main Influence

TWB and its forming technology play important role in lightweight manufacturing for the automobile parts. The weld-line movement during TWB forming process affects the product quality greatly. In this paper, two main influence factors of the movement, BHF and the blank thickness at the both sides of the weld-line, were studied by both the experiments and finite element simulation. The results showed that BHF has significant impact on the weld-line movement, especially when the thickness difference of the blanks in TWB is beyond a certain range. Besides, suitable BHF and thickness of the blanks can not only control the weld-line movement, but also improve the formability of TWB.

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