scholarly journals A Comparative Evaluation of Predictive Models of the Flat Rolling Process

2018 ◽  
Author(s):  
Máté Szűcs ◽  
György Krállics ◽  
John Lenard
Keyword(s):  
Element Model ◽  
Rolling Process ◽  
Dimensional Model ◽  
Rigid Plastic ◽  
One Dimensional ◽  
Inverse Approach ◽  
Friction Factors ◽  
Roll Flattening ◽  
The Coefficient Of Friction ◽  
Flat Rolling

The predictive abilities of several mathematical models of the cold, flat rolling process are tested by comparing their predictions to experimental measurements. The models include an empirical model, a one-dimensional model, a finite element model and an upper bound model. The coefficient of friction and the friction factor are first determined by the inverse approach, using the model deemed to be the most comprehensive. The effects of including or excluding an account of roll flattening, using elastic-plastic or rigid-plastic strips, and constant or velocity dependent coefficients of friction or friction factors are examined.

Microfluidic Cell Heating Characterized by 3-ω Measurements

2008 ◽  
Author(s):  
Thomas Barilero ◽  
Thomas Le Saux ◽  
Ludovic Julien ◽  
Vincent Croquette ◽  
Pierre-Olivier Chapuis ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Ion Beam ◽  
Element Model ◽  
Heat Diffusion ◽  
Dimensional Model ◽  
Ion Beam Etching ◽  
3Ω Method ◽  
One Dimensional ◽  
Microfluidic Chamber

Ion beam etching (IBE) was used to microfabricate resistive heaters in indium-tin-oxide (ITO). The device was then closed with a microfluidic chamber and its thermal behavior was investigated using the 3ω method. Experiments and finite element model (FEM) simulations both satisfactorily agreed with a simple one-dimensional model for heat diffusion.

Rigid-Plastic Finite Element Simulation of Deformation Mechanisms during Rolling of Complex Sheets Containing an Inclusion

2006 ◽  
Vol 306-308 ◽  
pp. 483-488 ◽  
Author(s):  
Dyi Cheng Chen
Keyword(s):  
Finite Element ◽  
Rolling Process ◽  
Deformation Mechanisms ◽  
Damage Factor ◽  
Rigid Plastic ◽  
Sheet Rolling ◽  
Friction Factors ◽  
Element Simulation ◽  
Simulation Results ◽  
Roll Gap

Using rigid-plastic finite element DEFORMTM 2D software, this study simulates the plastic deformation of complex sheets at the roll gap during the sheet rolling process. Specifically, the study addresses the deformation of complex sheets containing inclusion defects. Under various rolling conditions, the present numerical analysis investigates the damage factor distributions, the void length at the front and rear of the inclusion, the deformation mechanisms, and the stress-strain distributions around the inclusion. The relative influences of the thickness reduction, the roll radii, and the friction factors on the void length at the front and rear of the inclusion, respectively, are systematically examined. Additionally, the correlation between the front and rear void lengths and a series of damage factors is explored. The simulation results appear to verify the suitability of the DEFORMTM 2D software for modeling the rolling of complex sheets containing inclusions.

Minimization of Energy in the Multipass Rolling Process

1999 ◽  
Vol 123 (1) ◽  
pp. 135-141 ◽  
Author(s):  
M. Abdul Samad ◽  
Ravi S. Rao
Keyword(s):  
Process Model ◽  
Rolling Process ◽  
Design Parameters ◽  
Optimum Number ◽  
Frictional Stress ◽  
Total Load ◽  
Design Variables ◽  
Roll Flattening ◽  
Flat Rolling ◽  
Point Pressure

This research focuses on the optimization of the flat rolling process. In order to optimize the process effectively, the existing process model has been especially enhanced—in the neutral zone where the friction changes sign over a region rather than at a point. Pressure and frictional stress distributions as well as total load and torque are thereby estimated as functions of the various rolling parameters. Roll flattening has also been taken into account. The main problem of determining the optimum design parameters of multipass rolling has been considered. The problem has been formulated and solved as a constrained nonlinear programming problem by considering the radius of the rolls, the front and back tensions as design variables. Optimum number of passes have been found, so that the total energy consumed by the tandem mill is minimized. Constraints are placed on the induced stresses, the neutral angle, the angle of bite and the deflections of the rolls, for both cold and hot rolling processes.

Review and a Methodology to Investigate the Effects of Monolithic Channel Geometry

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Christopher D. Depcik ◽  
Austin J. Hausmann
Keyword(s):  
Thermal Stresses ◽  
Optimization Procedure ◽  
Momentum Equation ◽  
Circular Channel ◽  
Dimensional Model ◽  
Model Formulation ◽  
Channel Geometry ◽  
One Dimensional ◽  
Friction Factors ◽  
Catalytic Material

A typical monolithic catalyst consists of long, narrow, square channels containing a washcoat of catalytic material. While this geometry is the most common, other shapes may be better suited for particular applications. Of interest are hexagonal, triangular, and circular channel geometries. This paper provides a succinct review of these channel shapes and their associated heat and mass transfer correlations when used in a one plus one-dimensional model including diffusion in the washcoat. In addition, a summary of the correlations for different mechanical and thermal stresses and strains are included based on channel geometry. By including the momentum equation in the model formulation with geometry specific friction factors, this work illustrates a unique optimization procedure for light off, pressure drop, and lifetime operation according to a desired set of catalyst specifications. This includes the recalculation of washcoat thickness and flow velocity through the channels when cell density changes.

scholarly journals An Efficient Dynamic Modeling Technique for a Central Tie Rod Rotor

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jingze Liu ◽  
Qingguo Fei ◽  
Shaoqing Wu ◽  
Zhenhuan Tang ◽  
Sanfeng Liao ◽  
...  
Keyword(s):  
High Efficiency ◽  
Experimental Testing ◽  
Research Work ◽  
Three Dimensional ◽  
Element Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Mass Model ◽  
One Dimensional ◽  
Three Dimensional Finite Element

Compared with the three-dimensional rotor model for a central tie rod rotor, an equivalent one-dimensional model can greatly improve the computational efficiency in rotor dynamics analysis with a certain accuracy. However, little research work can be found on improving the modeling accuracy of one-dimensional models using experimental data. In this paper, a one-dimensional discrete mass model considering pretightening force is proposed for central tie rod rotors to achieve the purpose of both efficient and accurate modeling. Experimental testing and three-dimensional model analysis are used as reference and verification approaches. A sensitivity-based method is adopted to update the proposed one-dimensional model via minimizing the error in the critical speed comparing with the corresponding three-dimensional finite element model which has been verified by a modal test. Prediction of damped unbalanced response is conducted to show the practicality of the updated one-dimensional model. Results show that the method presented in this research work can be used to simulate a complex preloaded rotor system with high efficiency and accuracy.

A simplified model for estimating axial impact forces resulting from debris with non-uniform nonstructural mass

2016 ◽  
Vol 20 (6) ◽  
pp. 963-975 ◽  
Author(s):  
Payam Piran Aghl ◽  
Clay J Naito ◽  
H Ronald Riggs
Keyword(s):  
Impact Force ◽  
Element Model ◽  
Steel Tube ◽  
Elastic Response ◽  
Dimensional Model ◽  
Axial Impact ◽  
One Dimensional ◽  
Impact Forces ◽  
The Impact ◽  
Peak Impact Force

The impact forces resulting from the debris strikes during tsunami and flood events can lead to extreme damage to the structures located in inundation zones. It is important to estimate reliably such impact demands in order to design structures safely. This study is aimed to develop a simplified one-dimensional model to predict the impact force and duration for axial impact of the debris with non-uniformly distributed nonstructural mass. The focus herein is on in-air impact. An experimental study is carried out on a 6.1-m rectangular steel tube with different configurations of rigidly attached nonstructural mass under elastic response. A nonlinear dynamic finite element model of a steel tube with nonstructural mass is also developed and validated by comparing with the experimental data. Parametric studies are carried out to investigate the effect of nonlinearity on impact demands. The results reveal that the peak impact force is sensitive to the location of the nonstructural mass. It is also observed that the peak impact force is not affected by the magnitude of nonstructural mass during inelastic response. The experimental and simulation results are also used to assess the applicability of the simplified design-oriented one-dimensional model. It is found that the debris impact demands are well represented by the proposed one-dimensional model.

The Strain Analysis of Plate Cross Wedge Rolling of Spiral Shaft Parts

2014 ◽  
Vol 941-944 ◽  
pp. 1895-1900 ◽  
Author(s):  
Fa Shen ◽  
Wen Jing Yu ◽  
Wen Fei Peng ◽  
Xue Dao Shu ◽  
Chun Jie Yu
Keyword(s):  
Finite Element ◽  
Manufacturing Industry ◽  
Metal Flow ◽  
Strain Analysis ◽  
Element Model ◽  
Rolling Process ◽  
Cross Wedge Rolling ◽  
Rigid Plastic ◽  
Equipment Manufacturing ◽  
Deform 3D

The spiral shaft parts have been widely applied in machinery and equipment manufacturing industry, the paper based on DEFORM-3D, the rigid-plastic finite element model of cross wedge rolled spiral shaft parts was established. The rolling process was simulated, the strain laws were analyzed, and the characteristics of metal flow were explored. From which we can find Plate cross wedge rolled spiral shaft parts is completely feasible. The results provide the theoretic basis for precision deformation of cross wedge rolled spiral shaft parts.

The Difficulties of Predicting the Coefficient of Friction in Cold Flat Rolling

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Máté Szűcs ◽  
György Krallics ◽  
John G. Lenard
Keyword(s):  
Cold Rolling ◽  
Coefficient Of Friction ◽  
Rolling Process ◽  
Technical Literature ◽  
Steel Strips ◽  
The Coefficient Of Friction ◽  
Flat Rolling ◽  
Frictional Forces ◽  
Predictive Relations ◽  
Roll Gap

Abstract The flat rolling process is initiated when the frictional forces draw the strip to be rolled into the roll gap. These forces depend on the coefficient of friction, knowledge of which is essential to understand, describe, and analyze the process. Several predictive formulae for the coefficient have been presented in the technical literature. Contradictions are observed, however, when their predictions are compared to each other. The data obtained while cold rolling aluminum and steel strips are used in the analyses. A model of the rolling process—accounting for strain hardening, frictional events, and varying speeds—is then used to determine the coefficients of friction. The use of statistical analyses is found to yield more reliable results than the use of the predictive relations.

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