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.

The Influence of the Blank Holder Force during Forming Process of a U-Shaped Part Made from AZ31 Magnesium Alloy

2015 ◽  
Vol 809-810 ◽  
pp. 265-270
Author(s):  
Aurelian Albut ◽  
Valentin Zichil ◽  
Adrian Judele
Keyword(s):  
Magnesium Alloy ◽  
Sheet Metal ◽  
Elastic Recovery ◽  
Rolling Direction ◽  
Sheet Thickness ◽  
Bending Moment ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Shaped Part

In case of sheet metal forming the main dimensional errors are caused by the springback phenomena. The present work deals with numerical simulation related to draw bending and springback of U - shaped part made from magnesium alloy. The current paper is trying to prove out the important role of the blank holder force with respect to the forming process. Though novel approaches relating to the formality of magnesium alloy sheets, the change of springback due to the characteristic of each process should be verified by finite element method. Springback refers to the elastic recovery of deformed parts. Springback occurs because of the elastic relief from the bending moment imparted to the sheet metal during forming. Springback is mainly influenced by the sheet thickness, the punch and die profile radii, initial clearance between punch and die, friction conditions, rolling direction of the materials, blankholder force and by material properties. In this study, the magnesium alloy strips with two types of material having the thickness of 1mm, are used to investigate springback characteristics in U-shape bending. The Dynaform 5.6 software was used to simulate the forming process, in which the blank holder force takes values between 15 and 35 kN. In this study, the springback was analyzed by U-forming at room temperature conditions with different blank holder forces. Springback decreased with the increase of the blank holding force. Excessive holding force cause irregular thinning of the material, especially in the radius area.

Simulation Study on Forming Process of the Inner Panel of Automobile Front Fender

2011 ◽  
Vol 291-294 ◽  
pp. 335-338
Author(s):  
Ying Tong
Keyword(s):  
Simulation Study ◽  
Drawing Process ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Simulation Results ◽  
Forming Defects

According to the shape character of some one automobile inner panel of front fender the forming steps characterized by some process combined was brought forward. Based on FEM software the drawing process was simulated by a blank-holder force scheme 100000N, 200000N, 300000N. As the simulation results, in order to eliminate the fractures in diagonal reinforcements, it is infeasible only to decrease blank-holder force, but enlarging the die round corner is necessary. As fractures have been eliminated, in order to eliminate wrinkles, the blank-holder force needs to be increased. Otherwise the wrinkle region can be confined into useless area which needs to be cut off. Finally none forming defects occur as blank-holder force 300000N and die round corner 5mm.

Estimation of Optimal Blank Holder Force Trajectories in Segmented Binders Using an ARMA Model

2003 ◽  
Vol 125 (4) ◽  
pp. 763-770 ◽  
Author(s):  
Neil Krishnan ◽  
Jian Cao
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Moving Average ◽  
Arma Model ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Modes Of Failure ◽  
System Input

Sheet metal forming is one of the most important and frequently used manufacturing processes in industry today. One of the key parameters affecting the forming process is the blank holder force (BHF). In the past, researchers have demonstrated the advantages of varying the blank holder force during the forming process, that is, the two primary modes of failure in sheet metal forming (wrinkling and tearing) are avoided. This gives rise to improved formability, higher accuracy and better part consistency. In recent years, researchers have also shown increasing interest in forming processes where the blank holder force is varied spatially with the help of segmented binders or flexible binders. In this paper, we have combined the above two aspects and used a robust method to determine the blank holder force trajectories for a non-circular part using segmented binders. The proposed strategy is verified by implementing it into a finite element simulation. Binder force is treated as a system input. The displacement of the binder is used as a measure of the tendency to wrinkle, and is therefore treated as a system output. The parameters of the system are continuously identified and updated using a deterministic Auto-Regressive Moving-Average model (ARMA). The model is then used to control the binder displacement to a prescribed value by adjusting the system input, i.e., the binder force. In this manner, individual binder force profiles for each of the segmented binders are obtained. Due to the generic nature of the ARMA model, the strategy proposed in this paper can be applied to a variety of forming problems, making it a robust approach.

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.

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.

Study on Blank Holder Force Control in Sheet Metal Forming Process

2012 ◽  
Vol 182-183 ◽  
pp. 1605-1608
Author(s):  
Xiao Juan Lin ◽  
Jian Hua Wang ◽  
Ke Gao Liu
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Main Function ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Variable Blank Holder Force ◽  
The Status ◽  
Metal Forming Process

BHF is an important technical parameter in sheet metal forming, its main function is controlling material flowing，avoiding wrinkling and fracture. The status of study on the control technology of variable blank holder force (VBHF) was summarized, focusing on the method of optimized controlling and the theory of developing trend of VBHF is introduced in the paper.

A New Stretch-Forming Process Based on Loading at Discrete Points and its Numerical Investigation

2013 ◽  
Vol 423-426 ◽  
pp. 737-740
Author(s):  
Zhong Yi Cai ◽  
Mi Wang ◽  
Chao Jie Che
Keyword(s):  
Sheet Metal ◽  
Three Dimensional ◽  
Discrete Point ◽  
Stretch Forming ◽  
Sheet Metal Part ◽  
Metal Part ◽  
Forming Process ◽  
Loading Trajectory ◽  
New Process ◽  
Forming Defects

A new stretch-forming process based on discretely loading for three-dimensional sheet metal part is proposed and numerically investigated. The gripping jaw in traditional stretch-forming process is replaced by the discrete array of loading units, and the stretching load is applied at discrete points on the two ends of sheet metal. By controlling the loading trajectory at the each discrete point, an optimal stretch-forming process can be realized. The numerical results on the new stretch-forming process of a saddle-shaped sheet metal part show that the distribution of the deformation on the formed surface of new process is more uniform than that of traditional stretch-forming, and the forming defects can be avoided and better forming quality will be obtained.

Finite Element Analysis of Incremental Sheet Forming for Metal Sheet

2018 ◽  
Vol 783 ◽  
pp. 148-153
Author(s):  
Muhammad Sajjad ◽  
Jithin Ambarayil Joy ◽  
Dong Won Jung
Keyword(s):  
Mechanical Properties ◽  
Sheet Metal ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Machining Process ◽  
Machining Parameters ◽  
Forming Process ◽  
Element Analysis ◽  
Tool Diameter

Incremental sheet metal forming, is a non-conventional machining process which offers higher formability, flexibility and low cost of production than the traditional conventional forming process. Punch or tool used in this forming process consecutively forces the sheet to deform locally and ultimately gives the target profile. Various machining parameters, such as type of tool, tool path, tool size, feed rate and mechanical properties of sheet metal, like strength co-efficient, strain hardening index and ultimate tensile strength, effects the forming process and the formability of final product. In this research paper, Single Point Incremental Forming was simulated using Dassault system’s Abaqus 6.12-1 and results are obtained. Results of sheet profile and there change in thickness is investigated. For this paper, we simulated the process in abaqus. The tool diameter and rotational speed is find out for the production of parts through incremental forming. The simulation is done for two type of material with different mechanical properties. Various research papers were used to understand the process of incremental forming and its simulation.

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