An Approach for Modeling Sheet Metal Forming for Process Controller Design

1999 ◽  
Vol 122 (4) ◽  
pp. 717-724 ◽  
Author(s):  
C.-W. Hsu ◽  
A. G. Ulsoy ◽  
M. Y. Demeri
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Model Uncertainty ◽  
Metal Forming ◽  
Process Model ◽  
Controller Design ◽  
Blank Holder Force ◽  
Punch Force ◽  
Blank Holder ◽  
Blank Size

Varying the blank holder force during forming can lead to higher formability and accuracy, and better part consistency. Process control, using on-line adjustment of the blank holder force to follow a reference process variable (e.g., the punch force, the draw-in, etc.) trajectory has been applied to sheet metal forming. However, process controller design has not been thoroughly addressed. In this paper, the essential part for systematic process controller design, i.e., modeling a sheet metal forming process, will be addressed in terms of control terminology (e.g., the process model, the model uncertainty and the disturbance). A process model for u-channel forming, i.e., a mathematical relationship between the blank holder force and the punch force, is presented and experimentally validated. Characterization of the model uncertainty mainly due to small variations in blank size, sheet thickness, material properties and tooling shape due to die wear and the disturbance which is mainly due to friction is developed. [S1087-1357(00)01304-6]

Multi-Input Multi-Output (MIMO) Modeling and Control for Stamping

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Yongseob Lim ◽  
Ravinder Venugopal ◽  
A. Galip Ulsoy
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Material Flow ◽  
Process Model ◽  
Complex Geometry ◽  
Flow Characteristics ◽  
Forming Process ◽  
Punch Force ◽  
Force System

The binder force in sheet metal forming controls the material flow into the die cavity. Maintaining precise material flow characteristics is crucial for producing a high-quality stamped part. Process control can be used to adjust the binder force based on tracking of a reference punch force trajectory to improve part quality and consistency. The purpose of this paper is to present a systematic approach to the design and implementation of a suitable multi-input multi-output (MIMO) process controller. An appropriate process model structure for the purpose of controller design for the sheet metal forming process is presented and the parameter estimation for this model is accomplished using system identification methods. This paper is based on original experiments performed with a new variable blank holder force (or variable binder force) system that includes 12 hydraulic actuators to control the binder force. Experimental results from a complex-geometry part show that the MIMO process controller designed through simulation is effective.

scholarly journals Die design optimization on sheet metal forming with considering the phenomenon of springback to improve product quality

2018 ◽  
Vol 154 ◽  
pp. 01105 ◽  
Author(s):  
Agung Setyo Darmawan ◽  
Agus Dwi Anggono ◽  
Abdul Hamid
Keyword(s):  
Product Quality ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Die Design ◽  
Forming Limit ◽  
Improve Product Quality ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Improve Product

The process of sheet metal forming is one of the very important processes in manufacture of products mainly in the automotive field. In sheet metal forming, it is added a certain size at the die to tolerate a result of the elasticity restoration of material. Therefore, when the product is removed from the die then the process elastic recovery will end within the allowable tolerance size. Extra size of the die is one method to compensate for springback. The aim of this research is to optimize the die by entering a springback value in die design to improve product quality that is associated with accuracy the final size of the product. Simulation processes using AutoForm software are conducted to determine the optimal parameters to be used in the forming process. Variations the Blank Holder Force of 77 N, 97 N, and 117 N are applied to the plate material. The Blank Holder Force application higher than 97 N cannot be conducted because the Forming Limit Diagram indicates the risk of tearing. Then the Blank Holder Force of 37 N, 57 N and 77 N are selected and applied in cup drawing process. Even though a few of wrinkling are appear, however there is no significant deviation of dimension between the product and the design of cup.

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.

Improving the Quality in Deep Drawing of Rectangle Parts Using Variable Blank Holder Force

2010 ◽  
Vol 37-38 ◽  
pp. 521-524
Author(s):  
Yu Qing Shi
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Failure Modes ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Variable Blank Holder Force

Wrinkling and tearing are the main failure modes in sheet-metal forming. Wrinkle may occur at the start of a punch stroke if the blank-holder force (BHF) is too low, and tearing may occur at the end of a stroke if the BHF is too high. The BHF is important for deep-drawing because of an effective way to promote deep formability sheet metal. They can be reduced or eliminated by manipulating a suitable BHF during sheet-metal forming. This paper presented an attempt to determine the effect of variable BHF on the tearing and wrinkling and investigated using 08Al sheet metal. The experiment show that tearing and wrinkling can be eliminated and the quality of deep drawing of rectangle parts can be improved using variable BHF.

scholarly journals Design optimization of variable blank holder force trajectory and slide velocity in sheet metal forming

2018 ◽  
Vol 84 (863) ◽  
pp. 18-00162-18-00162 ◽  
Author(s):  
Masaki YOKOYAMA ◽  
Satoshi KITAYAMA ◽  
Kiichiro KAWAMOTO ◽  
Takuya NODA ◽  
Takuji MIYASAKA ◽  
...  
Keyword(s):  
Design Optimization ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Variable Blank Holder Force ◽  
Slide Velocity

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.

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