Advanced Forming Process Model - AFPM

2013 ◽  
pp. 383-401 ◽  
Author(s):  
K. Großmann ◽  
A. Hardtmann ◽  
H. Wiemer ◽  
L. Penter ◽  
S. Kriechenbauer
Keyword(s):  
Process Model ◽  
Forming Process

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.

The advanced forming process model including the elastic effects of the forming press and tool

2008 ◽  
Vol 8 (3) ◽  
pp. 41-54 ◽  
Author(s):  
KNUT GROßMANN ◽  
HAJO WIEMER ◽  
ANDRE HARDTMANN ◽  
LARS PENTER
Keyword(s):  
Process Model ◽  
Forming Process

scholarly journals Forming Control of Rheological Objects Using Forming Process Model.

2002 ◽  
Vol 20 (7) ◽  
pp. 717-724
Author(s):  
Shinichi Tokumoto ◽  
Shinichi Hirai
Keyword(s):  
Process Model ◽  
Forming Process

Stretch Forming Process Modeling: The Role of Modern Stretch Forming Machinery Design and Performance

2000 ◽  
Author(s):  
James M. Widmann
Keyword(s):  
Control System ◽  
Process Model ◽  
Local Buckling ◽  
Analytical Models ◽  
Hydraulic Control ◽  
Stretch Forming ◽  
Forming Process ◽  
Tensile Direction ◽  
Non Linear ◽  
Hydraulic Control System

Abstract Extrusion stretch forming is used extensively in the aerospace and architectural industries to add contour to extrusions and roll formed sections. Frame members, stringers, wing spars, curtain tracks and many other important aircraft parts are formed with this process. Forming is achieved by pulling an initially straight part in the tensile direction above the material’s yield point and then wrapping the section around a die to add contour. Local buckling and wrinkling that might appear in a pure bending operation can be avoided. There is current interest in improving the process for greater repeatability and less part rework to reduce cost while achieving tighter tolerances (e.g. [1,2]). The stretch forming die plays a significant role in the process. To this end researchers are interested in quicker die development techniques using non-linear beam theory and non-linear finite element modeling of the forming process. For a complete analytical picture of the process, a close look at the stretch forming machine’s performance must be included in the process model. Two major areas of machine performance are important; machine deflections and hydraulic control system performance. This paper provides a brief overview of the extrusion stretch forming process and then focuses on the structural and control system design of the modern stretch forming machine. Analytical models of the machine deflection as well as its hydraulic control system are developed. A short discussion concerning the difference between traditional “pressure forming” and modern CNC position forming is also included. Insight into the limitations of traditional PID control for the stretch forming machine can be seen from the analysis. It is evident that these machine models must be used to complete the process model to effectively create die designs for close tolerance and highly repetitive part production.

Computer Aided Modelling of Rubber Pad Forming Process

2011 ◽  
Vol 473 ◽  
pp. 637-644 ◽  
Author(s):  
Antonio del Prete ◽  
Gabriele Papadia ◽  
Barbara Manisi
Keyword(s):  
Sheet Metal ◽  
Process Model ◽  
Process Analysis ◽  
Low Cost ◽  
Critical Parameters ◽  
Forming Process ◽  
Small Series ◽  
Rubber Pad Forming ◽  
Rubber Forming ◽  
Rigid Die

Rubber pad forming (RPF) is a novel method for sheet metal forming that has been increasingly used for: automotive, energy, electronic and aeronautic applications [1]. Compared with the conventional forming processes, this method only requires one rigid die, according to the shape of the part, and the other tool is replaced by a rubber pad [1]. This method can greatly improve the formability of the blank because the contact surface between the rigid die and the rubber pad is flexible. By this way the rubber pad forming enables the production of sheet metal parts with complex contours and bends. Furthermore, the rubber pad forming process is characterized by a low cost of the die because only one rigid die is required [2]. The conventional way to develop rubber pad forming processes of metallic components requires a burdensome trial-and-error process for setting-up the technology, whose success chiefly depends on operator’s skill and experience [4][5]. In the aeronautical field, where the parts are produced in small series, a too lengthy and costly development phase cannot be accepted. Moreover, the small number of components does not justify large investments in tooling. For these reasons, it is necessary that, during the conceptual design, possible technological troubles are preliminarily faced by means of numerical simulation [4],[6]. In this study, the rubber forming process of an aluminum alloy aeronautic component has been explored with numerical simulations and the significant parameters associated with this process have been investigated. Several effects, depending on: stamping strategy, component geometry and rubber pad characterization have been taken into account. The process analysis has been carried out thanks to an extensive use of a commercially finite element (FE) package useful for an appropriate set-up of the process model [7],[8]. These investigations have shown the effectiveness of simulations in process design and highlighted the critical parameters which require necessary adjustments before physical tests.

Control of the Fabrication of Long Slender Workpieces of Arbitrary Shape—Part I: Open-Loop Control of the Multi-Axis Bending Process

1996 ◽  
Vol 118 (3) ◽  
pp. 540-548 ◽  
Author(s):  
J. X. Luo ◽  
D. L. Joynt ◽  
K. A. Stelson
Keyword(s):  
Arbitrary Shape ◽  
Process Model ◽  
Traditional Approach ◽  
Open Loop ◽  
Lead Times ◽  
Forming Process ◽  
Great Cost ◽  
Loop Control ◽  
Geometrical Concept ◽  
Metal Forming Process

Computer numerically controlled (CNC) multi-axis bending is a new metal-forming process used to fabricate long slender workpieces of arbitrary shape and cross section. This process can achieve higher productivity and flexibility than conventional forming processes. However, a manual trial-and-error process has been adopted to find control commands that would produce accurate part shape in mass production. This traditional approach which completely relies on the skills of the machine operator often results in long lead-times and great cost in setting up the bender for a new part. A new methodology has been developed, using the geometrical concept of intrinsic part representation, to model the workpiece and fabricating process. The process model compensates for elastic and fabricating process. The process model compensates for elastic springback, and can be used to predict a set of initial multi-axis control commands which will eventually converge to the final commands through a feedback process. The effectiveness of the method has been demonstrated experimentally.

Formability Enhancement of Al-Mg Sheet by Using Hydro-Mechanical Forming

2014 ◽  
Vol 622-623 ◽  
pp. 359-364
Author(s):  
Yong Nam Kwon ◽  
Sang Woo Kim ◽  
Young Seon Lee
Keyword(s):  
Deep Drawing ◽  
Process Model ◽  
Practical Application ◽  
Complicated Shape ◽  
Forming Process ◽  
Automotive Part ◽  
Single Sheet ◽  
Model Geometry ◽  
Technical Features ◽  
Al 5052 Alloy

Hydro-mechanical forming of Al sheet was investigated in the present study in order to fabricate automotive part having a complicated shape using Al 5052 alloy with a conventional formability which has been known to be quite lower compared to deep drawing steels. We have designed the hydro-mechanical forming in which Al sheet was drawn to a kind of preform step following gas blow forming for final accurate geometry. In order to judge a formability enhancement of Al sheet in terms of forming process, model geometry came from a practical automotive part which had quite depth with complicated curvatures, which was proven that a single sheet forming could not gave a successful part. Experimentally, we succeeded to make the model part with accurate dimension. The optimum forming conditions for respective forming steps were considered most important technical features of this hydro-mechanical. Also, the effort to avoid detrimental microstructure evolutions was given and discussed for a practical application.

Analysis of elastic rolling stand deformation and interstand tension effects on section faults of hot rolled wire rod and bars

2020 ◽  
Vol 87 (5) ◽  
pp. 343-348 ◽  
Author(s):  
Christian Overhagen ◽  
Rolf Braun ◽  
Rüdiger Deike
Keyword(s):  
Process Model ◽  
Dimensional Accuracy ◽  
Rolling Process ◽  
Process Models ◽  
Forming Process ◽  
Wire Rod ◽  
Metal Forming Process ◽  
Inline Measurement ◽  
Hot Rolled ◽  
Rolled Wire

AbstractThe present work aims at the modelling and simulation of the hot rolling process for wire rod and bars. After the fundamentals of plasticity, which are essential for the understanding of the process characteristics have been described, typical section deviations that can be expected in wire rod and bar mills are calculated with help of a numerical simulation model. The model allows the calculation of section shapes under the influence of elastic rolling stand deformations and interstand tensions. From this computational assessment of section faults, the necessity of inline measurement and process control for wire rod and bar mills is shown. This work is part of the PIREF project which incorporates the development of sensors, control systems and process models in order to control the dimensional accuracy of hot rolled wire rod and bars. The metal forming process model, as described here is used internally as a model for the static and kinematic interactions in the rolling process inside of the control model.

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