Combination of Finite-Element and Semi-Analytical Models for Sheet Metal Leveling Simulation

2011 ◽  
Vol 473 ◽  
pp. 182-189
Author(s):  
Amine Amor ◽  
Mohamed Rachik ◽  
Hédi Sfar
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Element Model ◽  
Rolling Process ◽  
Process Efficiency ◽  
Analytical Models ◽  
Initial Shape ◽  
Residual Curvature ◽  
Matlab Programming ◽  
Alternating Bending

Coiled sheet metal often exhibits shape defects that result from the rolling process or the coiling operation. To meet the quality requirement, these defects need to be removed using leveling and straightening. The process efficiency strongly depends on several parameters like the machine design, the rollers penetration and the sheet metal. Consequently, the leveling process is very sensitive and it is difficult to find the appropriate setting using trial and error procedure. In this context, numerical simulation can be very helpful. The aim of our work is to predict the residual curvature of the sheet knowing its initial shape and the leveling process settings. The simulation is carried out in two steps to integrate the global and the local behavior of the strip along the leveling process. In the first step, a 2D finite element model is used to predict the sheet metal deformations under the rollers action. In this first step the strip curvatures along the leveling machine are predicted. The so obtained results are then used to simulate the alternating bending and the spring back of the strip with the help of a semi-analytical model using the MATLAB programming environment. To validate the proposed approach, leveling tests were carried out on a 2.5 mm thickness sheet of DX51 steel and the measured residual curvatures are compared with the predictions. These comparisons show that satisfactory predictions can be obtained with good computational efficiency.

Accurate Evaluation of Bolt and Clamped Members Stiffnesses Of Bolted Joints

2021 ◽  
Author(s):  
Rashique Iftekhar Rousseau ◽  
Abdel-Hakim Bouzid ◽  
Zijian Zhao
Keyword(s):  
Finite Element ◽  
Joint Stiffness ◽  
Element Model ◽  
Fe Analysis ◽  
Bolted Joints ◽  
Analytical Models ◽  
Fe Modeling ◽  
Bolted Joint ◽  
A New Technique ◽  
External Loads

Abstract The axial stiffnesses of the bolt and clamped members of bolted joints are of great importance when considering their integrity and capacity to withstand external loads and resist relaxation due to creep. There are many techniques to calculate the stiffnesses of the joint elements using finite element (FE) modeling, but most of them are based on the displacement of nodes that are selected arbitrarily; therefore, leading to inaccurate values of joint stiffness. This work suggests a new method to estimate the stiffnesses of the bolt and clamped members using FE analysis and compares the results with the FE methods developed earlier and also with the existing analytical models. A new methodology including an axisymmetric finite element model of the bolted joint is proposed in which the bolts of different sizes ranging from M6 to M36 are considered for the analysis to generalize the proposed approach. The equivalent bolt length that includes the contribution of the thickness of the bolt head and the bolt nominal diameter to the bolt stiffness is carefully investigated. An equivalent bolt length that accounts for the flexibility of the bolt head is proposed in the calculation of the bolt stiffness and a new technique to accurately determine the stiffness of clamped members are detailed.

Tail Deviation Mechanism and Neural Network Control of the Tandem Rolling Strap

2011 ◽  
Vol 103 ◽  
pp. 488-492
Author(s):  
Guang Bin Wang ◽  
Xian Qiong Zhao ◽  
Yi Lun Liu
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Finite Element Model ◽  
Control Policy ◽  
Element Model ◽  
Rolling Process ◽  
Network Control ◽  
Neural Network Control ◽  
The Neural Network ◽  
The Finite Element Model

In the rolling process, deviation is the phenomenon that the strap width direction's centerline deviates from rolling system setting centerline,serious deviation will cause product quality drop and rolling equipment fault. This paper has established the finite element model to the hot tandem rolling aluminum strap, analyzed the strap’s deviation rule under four kinds of incentives,obtained the neural network predictive model and the control policy of the tail deviation.The result to analyze a set of fact deviation data shows this method may control tail deviation in preconcerted permission range.

FEM Simulation of Anisotropic Parameters Influencing the Earing in Sheet Metal Deep Drawing Process

2011 ◽  
Vol 88-89 ◽  
pp. 638-641 ◽  
Author(s):  
Lei Chen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sheet Metal ◽  
Deep Drawing ◽  
Fem Simulation ◽  
Element Model ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Material Characteristics

Earing is often undesirable in the production of deep drawn containers because it results in a nonuniform cup height. A finite element model for earring analysis is developed considering only the flange area of the sheet. It was found that the draw-in depth of the flange increases with the increase of the r value, and it remains invariable when r value is larger than 2. With the increase of the r value, the max thickness decreases and the min thickness increases. If △r>0, four earings are formed. If △r =0, the material characteristics in all the planar directions are same. The flange uniformly flows into the die cavity, no earing is formed. If △r<0, four earings are formed. The earing distribution is dominated by r0, r45 and r90. Both r and △r have much effect on the earing distribution.

Examination of Response of a Skewed Steel Bridge Superstructure During Deck Placement

2003 ◽  
Vol 1845 (1) ◽  
pp. 66-75 ◽  
Author(s):  
Elizabeth K. Norton ◽  
Daniel G. Linzell ◽  
Jeffrey A. Laman
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Analytical Models ◽  
Levels Of Analysis ◽  
Steel Bridge ◽  
Bridge Superstructure ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Skewed Bridge

The response of a 74.45-m (244-ft 0-in.) skewed bridge to the placement of the concrete deck was monitored to compare measured and predicted behavior. This comparison was completed to ( a) determine theoretical deflections and rotations with analytical models for comparison to actual deformations monitored during construction; ( b) compare the results of various levels of analysis to determine the adequacy of the methods; and ( c) examine variations on the concrete placement sequence to determine the most efficient deck placement methods. Two levels of analysis were used to achieve the objectives. Level 1 was a two-dimensional finite element grillage model analyzed with STAAD/Pro. Level 2 was a three-dimensional finite element model analyzed with SAP2000. These studies are discussed and findings are presented.

Process Characterization of Sheet Metal Spinning by Means of Finite Elements

2007 ◽  
Vol 344 ◽  
pp. 637-644 ◽  
Author(s):  
Gerd Sebastiani ◽  
Alexander Brosius ◽  
Werner Homberg ◽  
Matthias Kleiner
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Flexible Manufacturing ◽  
Theoretical Models ◽  
Element Model ◽  
Axially Symmetric ◽  
Element Analysis ◽  
Cross Sectional ◽  
Process Characterization ◽  
Metal Spinning

Sheet Metal Spinning is a flexible manufacturing process for axially-symmetric hollow components. While the process itself is already known for centuries, process planning is still based on undocumented expertise, thus requiring specialized craftsmen for new process layouts. Current process descriptions indicate a vast scope of different dynamic influences while the underlying mechanical model uses a simple static approach. Thus, a 3D Finite Element Model of the process has been set up at IUL in order to analyze the process in detail, providing online as well as cross sectional data of the specimen formed. Within the scope of this article, the results of the above mentioned Finite Element Analysis (FEA) are presented and discussed with respect to the qualitative stress distributions introduced in the existing theoretical models. Main emphasis of this paper is set on a discussion of the qualitative stress distribution, which is, to the current state, only known in theory.

scholarly journals Analysis of dynamic characteristics of climbing formwork under wind loads

2019 ◽  
Vol 79 ◽  
pp. 01016
Author(s):  
Shicheng Hu ◽  
Jun Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Calculation Method ◽  
Design Method ◽  
Element Model ◽  
Wind Load ◽  
Bending Effect ◽  
Matlab Programming ◽  
The Finite Element Model

This article took the climbing formwork which constructed on the bridge at a height of 100 meters as the prototype, then established the finite element model and conducted modal analysis. The APDL language is used to load the wind load which is simulated by the Matlab programming then calculated the displacement and acceleration responses of the climbing formwork and further. The results show that the bending effect of the climbing formwork is more obvious. This calculation method of calculating the wind load, improve the anti-wind design method of the climbing formwork.

scholarly journals Voltage Sources in 2D Fourier-Based Analytical Models of Electric Machines

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Bert Hannon ◽  
Peter Sergeant ◽  
Luc Dupré
Keyword(s):  
Finite Element ◽  
Great Majority ◽  
Element Model ◽  
Electric Machines ◽  
Analytical Models ◽  
Voltage Source ◽  
Pulse Width Modulated ◽  
Simulation Tools ◽  
Drive Trains ◽  
Terminal Voltage

The importance of extensive optimizations during the design of electric machines entails a need for fast and accurate simulation tools. For that reason, Fourier-based analytical models have gained a lot of popularity. The problem, however, is that these models typically require a current density as input. This is in contrast with the fact that the great majority of modern drive trains are powered with the help of a pulse-width modulated voltage-source inverter. To overcome that mismatch, this paper presents a coupling of classical Fourier-based models with the equation for the terminal voltage of an electric machine, a technique that is well known in finite-element modeling but has not yet been translated to Fourier-based analytical models. Both a very general discussion of the technique and a specific example are discussed. The presented work is validated with the help of a finite-element model. A very good accuracy is obtained.

Sheet Metals Forming Die Design Using Finite Element Analysis and the Taguchi Method

2014 ◽  
Vol 621 ◽  
pp. 195-201
Author(s):  
Surangsee Dechjarern ◽  
Maitri Kamonrattanapisut
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Coefficient ◽  
Taguchi Method ◽  
Finite Element Model ◽  
Sheet Metal ◽  
Element Model ◽  
Die Design ◽  
Forming Process ◽  
Element Analysis

Sheet metal deep-draw die is primarily constructed with draw bead, which is then modified based on trial and error to obtain a successful forming without splitting. This work aims at a robust design of forming die using numerical analysis and the Taguchi method. A three dimensional elastoplastic finite element model of a sheet metal forming process of SPCEN steel has been successfully developed using the material flow stress obtained from the modified Erichsen cup test. The model was validated with the actual forming experiment and the results agreed well. The influence of draw bead parameters on splitting and thinning distributions were examined using the Taguchi method. Four parameters, namely the friction coefficient, draw bead height, radius and shoulder radius were investigated. The Taguchi main effect analysis and ANOVA results show that the height and shoulder radius of the draw bead are the most important factor influencing the thinning distribution. Applying the Taguchi method and using the minimum thinning percentage as the design criteria, the optimum die design was identified as height, radius, shoulder radius and the friction coefficient of 4, 8, 8 mm and 0.125 respectively. The verified finite element model using the optimum die design was conducted. The predicted Taguchi response was within 5.9% from finite element analysis prediction. The improvement in the reduction of thinning percentage was 22.35%.

Description and Validation of a Finite Element Model of Backflow During Infusion Into a Brain Tissue Phantom

2012 ◽  
Vol 8 (1) ◽  
Author(s):  
José J. García ◽  
Ana Belly Molano ◽  
Joshua H. Smith
Keyword(s):  
Finite Element ◽  
Hydraulic Conductivity ◽  
Finite Element Model ◽  
Brain Tissue ◽  
Nonlinear Boundary ◽  
Fluid Pressure ◽  
Element Model ◽  
Analytical Models ◽  
External Boundary ◽  
Forward Flow

An axisymmetric biphasic finite element model is proposed to simulate the backflow that develops around the external boundary of the catheter during flow-controlled infusions. The model includes both material and geometric nonlinearities and special treatments for the nonlinear boundary conditions used to represent the forward flow from the catheter tip and the axial backflow that occurs in the annular gap that develops as the porous medium detaches from the catheter. Specifically, a layer of elements with high hydraulic conductivity and low Young’s modulus was used to represent the nonlinear boundary condition for the forward flow, and another layer of elements with axial hydraulic conductivity consistent with Poiseuille flow was used to represent the backflow. Validation of the model was performed by modifying the elastic properties of the latter layer to fit published experimental values for the backflow length and maximum fluid pressure obtained during infusions into agarose gels undertaken with a 0.98-mm-radius catheter. Next, the finite element model predictions showed good agreement with independent experimental data obtained for 0.5-mm-radius and 0.33-mm-radius catheters. Compared to analytical models developed by others, this finite element model predicts a smaller backflow length, a larger fluid pressure, and a substantially larger percentage of forward flow. This latter difference can be explained by the important axial flow in the tissue that is not considered in the analytical models. These results may provide valuable guidelines to optimize protocols during future clinical studies. The model can be extended to describe infusions in brain tissue and in patient-specific geometries.

Assessment of Corner Failure Depths in the Deep Drawing of 3D Panels Using Simplified 2D Numerical and Analytical Models

2000 ◽  
Vol 123 (2) ◽  
pp. 248-257 ◽  
Author(s):  
Hong Yao ◽  
Jian Cao
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Analytical Models ◽  
Design Stage ◽  
Beam Model ◽  
Preliminary Design ◽  
Powerful Means ◽  
Preliminary Design Stage ◽  
Blank Size

Methodologies of rapidly assessing maximum possible forming heights are needed for three-dimensional 3D sheet metal forming processes at the preliminary design stage. In our previous work, we proposed to use an axisymmetric finite element model with an enlarged tooling and blank size to calculate the corner failure height in a 3D part forming. The amount of enlargement is called center offset, which provides a powerful means using 2D models for the prediction of 3D forming behaviors. In this work, an analytical beam model to calculate the center offset is developed. Starting from the study of a square cup forming, a simple analytical model is proposed and later generalized to problems with corners of an arbitrary geometry. The 2D axisymmetric models incorporated with calculated center offsets were compared to 3D finite element simulations for various cases. Good assessments of failure height were obtained.

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