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.

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.

Comparison between laser beam and gas tungsten arc tailored welded blanks via deep drawing

2020 ◽  
pp. 095440542096239
Author(s):  
Ahmad Aminzadeh ◽  
Ali Parvizi ◽  
Rasoul Safdarian ◽  
Davood Rahmatabadi
Keyword(s):  
Laser Beam ◽  
Base Metal ◽  
Deep Drawing ◽  
Weld Zone ◽  
Weld Line ◽  
Gas Tungsten Arc ◽  
Tailor Welded Blanks ◽  
Gas Tungsten ◽  
Weld Line Movement ◽  
Line Movement

This paper aims at analyzing the deformation behavior of tailor welded blanks (TWBs), manufactured by laser beam welding (LBW) and gas tungsten arc welding (GTAW), through the deep drawing process. Dissimilar and similar steels with different thicknesses were used in the production of tailor welded blanks. The Nd: YAG laser welding method with nitrogen (N2) as the shielding gas was used to join TWBs. The effects of some significant process factors, namely welding speed, blank holder forces (BHF), material properties of base metals, dry/lubricated condition and laser spot size was experimentally investigated on the weld line movement and drawing depth. Results indicated that using LBW with optimum parameters for the production of dissimilar TWBs caused the control of failure in the weaker base metal. Results showed that the sound welds were produced in similar TWBs with a thickness ratio of 2 when using GTAW, but the weld quality was poor when using LBW. Moreover, it is observed that the critical stresses were taken place outside of the weld zone and rupture due to the high heat input of laser and metallurgical changes of the base metal that occur in the pre-softening zone. In addition, the weld line movement occurred as a result of plastic strain change of the weld joint that caused failure-prone zone creation as well as the adverse wrinkling.

Blank holder force optimisation strategy in deep drawing process

2007 ◽  
Vol 1 (2) ◽  
pp. 226 ◽  
Author(s):  
Hossam H. Gharib ◽  
Abdalla S. Wifi ◽  
Maher Y.A. Younan ◽  
Ashraf O. Nassef
Keyword(s):  
Deep Drawing ◽  
Drawing Process ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Deep Drawing Process

Minimization of weld line movement in heat-assisted forming of tailor welded blanks

2018 ◽  
Vol 233 (11) ◽  
pp. 3760-3768
Author(s):  
VVN Satya Suresh ◽  
Srinivasa Prakash Regalla ◽  
Amit Kumar Gupta
Keyword(s):  
Weld Line ◽  
Tungsten Inert Gas Welding ◽  
Selective Heating ◽  
Tailor Welded Blanks ◽  
Stamping Process ◽  
Steel Aisi ◽  
Tailor Welded Blank ◽  
Weld Line Movement ◽  
Line Movement

In this work, the formability aspects in terms of desired cup height during stamping operation of tailor welded blanks have been studied along with minimizing the movement of weld line. Circular sheets were prepared by joining austenitic stainless steel (ASS 304 Grade) and drawing quality mild steel (AISI 1018) materials with tungsten inert gas welding. To reduce the undesirable weld line movement during stamping process, a novel heat-assisted forming method involving localized and controlled heating of the stronger material side (ASS 304 steel) has been carried out. The experimental setup developed for this purpose enabled heating and maintained the selected zone at the desired temperature during the stamping process. The entire process has been simulated using finite element method and the results obtained were in close agreement with the experimental results. The effect of selective heating of tailor welded blank also resulted in the overall improvement in the quality of the product.

Redesign of a Complicated Component of Auto Body Based on the Properties of TWBs

2010 ◽  
Vol 97-101 ◽  
pp. 3151-3160
Author(s):  
Yu Ning ◽  
Ying Chun Han ◽  
Chun Yan Wang
Keyword(s):  
Mechanical Properties ◽  
Parametric Optimization ◽  
Weld Line ◽  
Mechanical Analysis ◽  
Parent Metal ◽  
Forming Technology ◽  
Auto Body ◽  
Weld Line Movement ◽  
Welding Position ◽  
Line Movement

With a synthetic study on the mechanical properties and deformability of TWBs, and an advanced mechanical analysis of weld-line movement, the theoretic basis for the whole forming and redesign of a complicated component of auto body (body side-inner panel) was achieved. Then a preliminary redesign was conducted with the selection and collocation of parent metal, the layout of the welding position, and the design of integral forming drawing taken into consideration. Thereafter, by simulation forming and parametric optimization, the redesign of the component was completed and its stamping forming technology was greatly improved.

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