scholarly journals Development on a Prediction Model for Experimental Condition of Flexibly Reconfigurable Roll Forming Process

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 896
Author(s):  
Ji-Woo Park ◽  
Jeong Kim ◽  
Beom-Soo Kang
Keyword(s):  
Regression Analysis ◽  
Regression Model ◽  
Sheet Metal ◽  
Quadratic Function ◽  
Target Surface ◽  
Total Sample ◽  
Roll Forming ◽  
Radius Of Curvature ◽  
Forming Process ◽  
Mean Square Errors

Flexibly-reconfigurable roll forming (FRRF) is a novel sheet metal forming technology by which sheet metal is shaped into a desired curvature using reconfigurable rollers and gaps. FRRF is conducive to producing multi-curvature surfaces by controlling the longitudinal strain distribution. However, it is difficult to predict the forming results since FRRF technology forms a secondary surface from the primary curvature. This study investigates the use of regression analysis as a basis for a model that can predict the longitudinal curvature of sheet metal. The following variables were considered as input parameters: Maximum compression value, radius of curvature in the transverse direction, and initial blank width. Regression model samples are obtained by performing experiments using FRRF equipment whilst the experimental design was generated by a three-level, three-factor full factorial design. The experimental surfaces are of a convex and of a saddle-type shape, with a total sample size of 54. Through regression analysis it has been shown that the longitudinal curvature can be expressed by means of a quadratic equation. The matching quadratic function was verified with R-squared values and root-mean-square errors, whilst the normality of the sample data was also verified. To apply the model to the actual forming process, the regression model was converted to deduce the compression characteristics for forming the target surface. Throughout the study, the proposed analytical procedure was validated, and a statistical formula for estimating the longitudinal curvature produced by the FRRF apparatus established.

Study on flexibly-reconfigurable roll forming process for multi-curved surface of sheet metal

2014 ◽  
Vol 15 (6) ◽  
pp. 1069-1074 ◽  
Author(s):  
Jun-Seok Yoon ◽  
So-Eun Son ◽  
Woo-Jin Song ◽  
Jeong Kim ◽  
Beom-Soo Kang
Keyword(s):  
Sheet Metal ◽  
Curved Surface ◽  
Roll Forming ◽  
Forming Process ◽  
Roll Forming Process

Modeling and Simulation of Continuous Flexible Roll Forming Process

2013 ◽  
Vol 365-366 ◽  
pp. 549-552
Author(s):  
Zhou Sui ◽  
Zhong Yi Cai ◽  
Ming Zhe Li
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Three Dimensional ◽  
Rigid Bodies ◽  
Roll Forming ◽  
Forming Process ◽  
Flexible Roll Forming ◽  
Flexible Roll ◽  
Roll Forming Process

The continuous flexible roll forming process is a novel sheet metal forming technique for effectively manufacture of three-dimensional surface parts. In this study, two types of finite element (FE) models were developed under the ABAQUS/Explicit environment. The difference of the two models is that the rolls are defined as discrete rigid bodies in model No.1 and are deformable in model No.2. An experiment was carried out using the continuous sheet metal forming setup. The comparison of the numerical computation results with the experimental results shows that the model No.2 can be used for the shape prediction of continuous flexible roll forming process well.

Three-Dimensional Numerical Simulation and Experimental Study of Sheet Metal Bending by Laser Peen Forming

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Yongxiang Hu ◽  
Yefei Han ◽  
Zhenqiang Yao ◽  
Jun Hu
Keyword(s):  
Numerical Model ◽  
Sheet Metal ◽  
Laser Energy ◽  
Three Dimensional ◽  
Target Surface ◽  
Thick Sheet ◽  
Specimen Thickness ◽  
Forming Process ◽  
Form Complex ◽  
Peen Forming

Laser peen forming (LPF) is a purely mechanical forming method achieved through the use of laser energy to form complex shapes or to modify curvatures. It is flexible and independent of tool inaccuracies that result from wear and deflection. Its nonthermal process makes it possible to form without material degradation or even improve them by inducing compressive stress over the target surface. In the present study, a fully three-dimensional numerical model is developed to simulate the forming process of laser peen forming. The simulation procedure is composed of several steps mainly including the shock pressure prediction, the modal analysis, and the forming process calculation. System critical damping is introduced to prevent unnecessary long post-shock residual oscillations and to greatly decrease the solution time for simulation. The bending profiles and angles with different thicknesses are experimentally measured at different scanning lines and scanning velocities to understand the process and validate the numerical model. The calculated bending profiles and angles agree well with the trend of the measured results. But it is found that simulations with the Johnson–Cook model are more consistent, matching the experimental results for the thick sheet metal with a convex bending, while the elastic-perfectly-plastic model produces a better agreement even though with underestimated values for the thinner sheet metal with a concave bending. The reason for this phenomenon is discussed, combining the effects of strain rate and feature size. Both the simulation and the experiments show that a continuous decrease in bending angle from concave to convex is observed with increasing specimen thickness in general. Large bending distortion is easier to induce by generating a concave curvature with LPF, and the angle of bending distortion depends on the number of laser shocks.

scholarly journals A Predictive Model of Flexibly-reconfigurable Roll Forming Process using Regression Analysis

2017 ◽  
Vol 207 ◽  
pp. 1266-1271
Author(s):  
Ji-woo Park ◽  
Min-gyu Kil ◽  
Jeong Kim ◽  
Beom-soo Kang
Keyword(s):  
Regression Analysis ◽  
Predictive Model ◽  
Roll Forming ◽  
Forming Process ◽  
Roll Forming Process

Roll Forming: Reusable Design and Quantifiable Design Effectiveness

2009 ◽  
Vol 410-411 ◽  
pp. 245-252 ◽  
Author(s):  
Diane J. Mynors ◽  
Martin English ◽  
Michael Castellucci
Keyword(s):  
Sheet Metal ◽  
Rolling Process ◽  
Roll Forming ◽  
Forming Process ◽  
Starting Point ◽  
Full Production ◽  
Sectional Profile ◽  
Tool Set ◽  
Design Effectiveness ◽  
Reusable Design

The cold rolled forming process passes flat sheet metal through a series of roll tool sets resulting in complex final section profiles. The sheet metal is deformed both while in contact with the rolls and while in between the roll. Some of the variables in this process include the roll tool set and hence progression design and the designer; the metal type and its thickness; and the sectional profile and the associated tolerances required by the customer. When a customer orders a new profile the roll tool and hence system designers’, start by trying to determine if something similar has previously been rolled. If a similar profile can be identified then that becomes the starting point for the new process design which includes the roll tool sets and the number of sets. Typically previous designs have been identified from the collective design office memory or by searching through past drawings until something similar is found. When a previous similar rolled section is identified; unless the design is very recent it is often impossible to gauge a measure of design and hence rolling success. This paper describes how the authors have developed and implemented within the Hadley Group a searchable database of previously rolled profiles, thus enabling all similar profiles to be identified. In addition, the paper contains a description of how a measure of tooling design effectiveness has been developed and is used as part of the full design, pre-production rolling, and full production rolling process with the results being incorporated into the database, hence enabling an informed selection of the design starting point.

A New Engineering Technique in Roller Design to Prevent Thinning of Sheet in Roll Forming Process

2017 ◽  
Vol 873 ◽  
pp. 42-47
Author(s):  
Dong Won Jung
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Metal Sheet ◽  
Roll Forming ◽  
Forming Process ◽  
Explicit Finite Element ◽  
Main Challenge ◽  
Engineering Technique ◽  
Roll Forming Process

These days sheet metal forming is a widely used in different industrial fields with large production volumes. Formability of metal sheets is limited by localized necking and plastic instability. In sheet metal forming processes like drawing and stamping the main challenge is thinning of the metal sheet in some regions. To reduce thinning of the sheet product, roll forming has been suggested instead of stamping process. Thinning strain can cause necking, tearing or wrinkling which are failure of the metal sheet. In this study a new engineering technique is proposed in order to prevent thinning of the steel galvanized hot coil commercial (SGHC) in roll forming process. An explicit finite element code, ABAQUS software, was used to simulate the roll forming process. The results show that the proposed technique has an important effect on thinning of the sheet and can reduce it significantly. Investigation on the second and third and fourth rollers show the effect of modified roller dimension as on reducing the thickness. These reductions in second, third and fourth rollers are from 4 percent to 0.5 percent, 2.8 to 1.4 percent and from 1.4 to 0.7 percent respectively. The reasons of the new techniques effect were also discussed.

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