Analysis of the Large Plastic Deformation Involved in Wear Processes Using the Finite Element Method With an Updated Lagrangian Formulation

1987 ◽  
Vol 109 (2) ◽  
pp. 330-337 ◽  
Author(s):  
Nobuo Ohmae
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Equivalent Stress ◽  
Lagrangian Formulation ◽  
The Finite Element Method ◽  
Large Plastic Deformation ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian ◽  
Element Method

Large plastic deformation caused by friction for high purity copper was investigated using the finite element method with an updated Lagrangian formulation. The phenomenological background of this large plastic deformation was studied with a scanning electron microscope, and the nucleation of voids similar to those obtained for copper rolled to over 50 percent reduction was observed. Void nucleation was found to correlate with the agglomeration of over-saturated vacancies formed under high plastic strains. The computer-simulation analyzed such heavy deformation with an equivalent stress greater than the tensile strength and with an equivalent plastic strain of 0.44. Crack propagation was discussed by computing the J-integrals.

Analysis of Optimal Vertical in Angular U-Bending Process

2011 ◽  
Vol 337 ◽  
pp. 346-349
Author(s):  
Tsung Chia Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Lagrangian Formulation ◽  
Blank Holder ◽  
Elastic Plastic ◽  
Metal Sheets ◽  
Bending Process ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian ◽  
Tool Angle

This study aims to analyze the effects of angular U-bending process on the springback of metal sheets. Based on Updated Lagrangian Formulation (ULF), the 3D incremental elastic-plastic Finite Element Method was inferred to simulate the U-bending process of metal sheets. The die/blank holder profile with angles of α=-4°, α=-2°, α=0°, α=2°, α=4° and die/punch profile with radiuses of Rp=Rd=6.0mm were analyzed to determine the influence of tool angles on the springback. With different tool angles to proceed the U-bending process of metal sheets, it is found that the larger or smaller die angles, the more springback magnitude. When perpendicular U-sheets are required, θ1 of the U-sheet presents 90 degree on the tool angle α=-1.2° and θ2 shows 90 degrees on the tool angle α=-0.4°. The aim of this study is to investigate the effects of angle variables on the springback in the U-bending process and to obtain useful data from the industrial field.

scholarly journals NUMERIC ANALYSIS OF LARGE PENETRATION OF THE CONE IN UNDRAINED SOIL USING FEM

2003 ◽  
Vol 9 (2) ◽  
pp. 122-131
Author(s):  
Darius Markauskas ◽  
Rimantas Kačianauskas ◽  
Rolf Katzenbach
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Solution ◽  
Cone Penetration ◽  
Penetration Process ◽  
Large Distortion ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian ◽  
Element Method ◽  
Undrained Soil

Numeric analysis of the large penetration of the cone in undrained soil using finite element method (FEM) is presented. Until now the computation procedures has not been developed to such an extent, that they could provide numerical solution of large cone penetration problem. In this paper for solving of the large cone penetration problem an updated Lagrangian formulation and finite element method are used. To overcome large distortion of the finite element geometry during cone penetration leading to illconditioning equations a remeshing technique is developed. The proposed remeshing technique enables the simulation of the penetration process until steady cone penetration is reached. The analysis of the cone penetration in undrained soil is provided. The comparison of current numerical results and other authors' results are presented.

scholarly journals Optimized Design of an ECAP Die Using the Finite Element Method for Obtaining Nanostructured Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Patricia Ponce-Peña ◽  
Edgar López-Chipres ◽  
Edgar García-Sánchez ◽  
Miguel Angel Escobedo-Bretado ◽  
Brenda Xiomara Ochoa-Salazar ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Tensile Strain ◽  
Fem Analysis ◽  
Optimized Design ◽  
The Finite Element Method ◽  
Angular Pressing ◽  
Cracking Tendency ◽  
Element Method

An alloy type A16060 was exposed to severe plastic deformation to study its reaction using the finite element method (FEM). To perform this, six different configurations were used in the design of the die’s channel for ECAP (equal channel angular pressing) to obtain nanostructure materials and to optimize the process. Thanks to simulation performed with FEM, it is possible to study the homogeneity in the deformation due to the variation of conditions affecting directly the material being processed using the ECAP technique, such as the friction coefficient, extrusion speed, and mainly the die’s channel geometry being utilized in the ECAP process. Due to the tensile strain area being located mainly in the upper part of the deformed test cylinder (plastic deformation area) which increases the fracture and cracking tendency preventing the processing through ECAP the die being utilized was modified to eliminate the tensile strain area favoring the appearance of compressive stress which reduces the cracking tendency and the fracture of the sample being processed. The FEM analysis demonstrated that the strain state changed significantly from tension to compression when the modified die was used, facilitating the processing of the piece by ECAP.

Analytical and Numerical Modelling of Strain and Strain Rate in Equal Channel Angular Pressing (ECAP)

2006 ◽  
Vol 306-308 ◽  
pp. 965-970
Author(s):  
Hyoung Seop Kim
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Strain Rate ◽  
Equal Channel Angular Pressing ◽  
The Finite Element Method ◽  
Angular Pressing ◽  
Geometric Conditions ◽  
Strain And Strain Rate ◽  
Element Method

Equal channel angular pressing (ECAP) is a convenient forming procedure among various severe plastic deformation processes. It is based on extruding material through specially designed entry and exit channel dies to produce an ultrafine grained microstructure. The properties of the materials obtained depend on the plastic deformation behaviour during ECAP, which is governed mainly by the die geometry, the material itself and the processing conditions. As the mechanical properties of the severely deformed material are directly related to the deformation history, understanding the phenomena associated with strain and strain rate development in the ECAP process is very important. In this study, the results of continuum modelling of ECAP are described in order to understand strain and strain developments. For this purpose, the results of modelling ECAP using the finite element method and analytical solution are presented for various geometric conditions. It was concluded that although deformation is nonuniform due to geometric effects, the strain and strain rate values obtained by the analytical solutions are not much different from the average results of the finite element method.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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