A strategy for the controlled setting of flatness and residual stress distribution in sheet metals via roller levelling

Grüber, Markus

doi:10.1016/j.proeng.2017.10.892

Cited by 21 publications

(17 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…(15) can be expressed as Eq. (16). The subscript of A 0 j represents the number of the calculated element and the superscript represents the number of iterations, as the solving process needs iteration.…”

Section: Contact Establishment Phasementioning

confidence: 99%

“…Despite being widely available, these models fail to satisfy the ever-increasing requirement for flatness, because the models do not fully consider the contact state between the plate and rollers. The second category consists of finite element method (FEM)-based and boundary element method (BEM)-based analytical models [16][17][18][19][20]. Huh et al [21] studied the sheet tension leveling process with the help of elastic-plastic finite element simulations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Model for the Whole Roller Leveling Process of Plates with Random Curvature Distribution Based on the Curvature Integration Method

Guan

Zhang

Zang

et al. 2019

Chin. J. Mech. Eng.

View full text Add to dashboard Cite

A model based on the curvature integration method has been applied in an online plate leveling system. However, there are some shortcomings in the current leveling models. On the one hand, the models cannot deal with the leveling process of plates with a random curvature distribution. On the other hand, the current models are suitable only for stable leveling processes and ignore the biting in and tailing out stages. This study presents a new plate-leveling model based on the curvature integration method, which can describe the leveling process of plates with random curvature distribution. Further, the model is solved in two cases in order to take the biting in and tailing out stages into consideration. The proposed model is evaluated by comparing with a plate leveling experiment. Finally, the leveling process of a plate with a wave bent is studied using the proposed model. It is found that the contact angles vary greatly during the biting in and tailing out stages. However, they are relatively steady during the 5 roller leveling stage. In addition, the contact angle of roller No. 2 is the smallest, which is close to 0. Roller leveling can effectively eliminate bending in the plate, but there are regions in the head and tail of the plate, where roller leveling is not effective. The non-leveling region length is about 2 times that of the roller space. This study proposes a quasi-static plate-leveling model, which makes it possible to analyze the dynamic straightening process using a curvature integration method. It also makes it possible to analyze the straightening process of a plate with random curvature distribution.

show abstract

Section: Contact Establishment Phasementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Model for the Whole Roller Leveling Process of Plates with Random Curvature Distribution Based on the Curvature Integration Method

Guan

Zhang

Zang

et al. 2019

Chin. J. Mech. Eng.

View full text Add to dashboard Cite

show abstract

“…Stadler et al investigated the curvature and the contact force at the striproll contact point of a metal strip in an experimental device and derived a material model and a steady-state strip deformation model to compute the feasible combinations of curvature and contact force [29]. Grüber and Hirt proposed a control strategy on a force measurement in the first load triangle of a leveling machine and investigated a feedforward control strategy based on control curves for varying yield strengths along the strip length [30,31]. Nikula et al analyzed the mechanical stress inflicted on a roller leveler processing cold steel strips based on a feature extracted from vibration measurements and introduced models specific to different steel grades to the prediction of the stress level [32,33].…”

Section: Introductionmentioning

confidence: 99%

A Novel Modeling Method in Metal Strip Leveling Based on a Roll-Strip Unit

Wang

2020

Mathematical Problems in Engineering

View full text Add to dashboard Cite

In the metal strip-multiroll leveling process, the action behavior of each roll is different. However, modeling each roll individually will result in redundancy which is not conducive to the modeling of the entire leveling process. To overcome this problem, a roll-strip unit (RSU) model is proposed to uniformly describe the behavior of each roll during the leveling process. The RSU and its equivalent model are defined on the basis of analyzing the force relationship between the roll and the strip. According to the linear distribution of the bending moment in the longitudinal direction of the strip, the position of the zero bending moment, that is, the virtual fulcrum, is obtained to determine the interval of the RSU. A plastic deformation function is established to describe the influence of plastic extension on the tension and velocity of the strip. The fitting of the deformation curve of the strip is optimized by the tension influence factor and the zero curvature moment. The static friction condition between the roll and the strip which ensures the normal operation of the RSU is given. The AMESim model of the RSU is established to lay the foundation for the dynamic modeling of the multiroll leveler.

show abstract

“…The primary method of reducing and eliminating residual stress is multi-roll levelling. The basic principle of multi-roll levelling is that a series of alternating and progressively decreasing loads are applied to the sheet by a set of work rolls of the leveller to cause multiple elastoplastic deformations and the residual stress in the sheet is gradually reduced until it is eliminated [9,10].…”

Section: Introductionmentioning

confidence: 99%

“…Tran et al investigated the experimental and numerical modelling of flatness defects in strip cold rolling, proposed an experimental setup to analyse the interaction between residual stress and buckling for wavy edge flatness defects, and used finite element simulation for test validation [35,36]. Grüber et al used a numerical model of a seven-roll leveller to determine roll positions resulting in a flat sheet and a defined residual stress distribution, measured the residual stresses across the sheet thickness after levelling using diffraction analysis [9,10].…”

Section: Introductionmentioning

confidence: 99%

Evolution of Residual Stress Based on Curvature Coupling in Multi-Roll Levelling

Liang

Wang

et al. 2019

Applied Sciences

View full text Add to dashboard Cite

Residual stress is the main cause of flatness defects in sheet metal and the basic method to improve the shape quality of the sheet is to reduce and eliminate the residual stress by multi-roll levelling. The curvature coupling between repeated sheet bendings in multi-roll levelling greatly affects the accuracy of the analysis of the residual stress evolution, which is rarely considered in current research. Aiming to address this problem, a method for eliminating residual stress by multi-roll levelling based on curvature coupling is discussed in this article. An evaluation criterion and an analysis model are proposed to investigate the evolution of the residual stress in multi-roll levelling considering the curvature coupling between bendings. The effects of the intermesh of the work rolls and the plastic deformation of the sheet on the residual stress are also discussed. The results show that multi-roll levelling will cause rolling residual stress while reducing the initial residual stress of the sheet and the larger plastic deformation caused by the intermesh of the work rolls at the entry is beneficial for the complete elimination of the initial residual stress, but the rolling residual stress will increase at the same time. Therefore, the total residual stress of the sheet after levelling depends on the appropriate levelling parameters.

show abstract

A strategy for the controlled setting of flatness and residual stress distribution in sheet metals via roller levelling

Cited by 21 publications

References 6 publications

Model for the Whole Roller Leveling Process of Plates with Random Curvature Distribution Based on the Curvature Integration Method

Model for the Whole Roller Leveling Process of Plates with Random Curvature Distribution Based on the Curvature Integration Method

A Novel Modeling Method in Metal Strip Leveling Based on a Roll-Strip Unit

Evolution of Residual Stress Based on Curvature Coupling in Multi-Roll Levelling

Contact Info

Product

Resources

About