Automatic Remeshing Scheme for Modeling Hot Forming Process

1986 ◽  
Vol 108 (4) ◽  
pp. 465-469 ◽  
Author(s):  
H. P. Wang ◽  
R. T. McLay
Keyword(s):  
Finite Element ◽  
Contact Point ◽  
Numerical Algorithms ◽  
Hot Forming ◽  
Temperature Sensitive ◽  
Forming Process ◽  
Contact Points ◽  
Moving Contact ◽  
Element Technique ◽  
Updated Lagrangian

Many intrinsic problems associated with the modeling of hot forming processes are described. In the updated Lagrangian finite element technique both the momentum and energy equations are formulated to accommodate moving meshes. Forming processes have several characteristics: no-slip conditions with transient free surfaces; strong thermal and flow coupling; and moving fluid/solid contact points. Due to the no-slip condition at the walls, the Lagrangian mesh is distorted. Two related numerical algorithms, an automatic remeshing scheme and a moving contact point definition, are developed and incorporated into a finite element code for incompressible viscous flow with temperature-sensitive viscosity. The application of this newly developed code for analyzing the glass pressing process demonstrates the capability of this powerful engineering tool.

scholarly journals Finite-element block shear failure deformation-to-fracture failure analysis

2020 ◽  
Vol 47 (4) ◽  
pp. 418-427 ◽  
Author(s):  
K.K. Adewole ◽  
Oladejo O. Joy
Keyword(s):  
Finite Element ◽  
Shear Deformation ◽  
Shear Failure ◽  
Tensile Deformation ◽  
Pure Shear ◽  
Contact Point ◽  
Shear Capacity ◽  
Total Load ◽  
Contact Points ◽  
Block Shear

This paper presents the finite-element (FE) block shear failure (BSF) deformation-to-fracture analysis. FE analysis reveals the following: BSF begins with bolt – bolt hole contact point compressive yielding and not the tensile or shear yielding reported in the literature. BSF does not result from the combination of the gauge tensile plane tensile deformation and the shear plane pure shear deformation alone as reported in the literature and codes. BSF results from compressive deformation of the bolt – bolt hole contact points, tensile deformation of bolt hole portions not in contact with the bolts, gauge tensile plane and edge distance tensile plane deformations in combination with pure shear deformation and a combined shear and tensile bending deformation of the portions of the shear planes near to and remote from the bolt – bolt hole contact points, respectively. This study provides a better understanding of the BSF mechanism, BSF total load-bearing areas, and various resistances to deformation that contribute to the block shear capacity.

The Design and Optimization of Large-Scales Heavy Gantry NC Machining Center Based on Finite Element Method

2011 ◽  
Vol 697-698 ◽  
pp. 656-660
Author(s):  
Shu Bo Xu ◽  
K.K. Sun ◽  
Cai Nian Jing ◽  
Guo Cheng Ren
Keyword(s):  
Finite Element ◽  
Contact Point ◽  
Large Diameter ◽  
Cnc Machining ◽  
Beam Structure ◽  
Maximum Displacement ◽  
Design And Optimization ◽  
Contact Points ◽  
Machining Center ◽  
Maximal Displacement

Large gantry machining center can be applied to large diameter and thickness of the flanges, tube sheets and other large sheet metal processing, the industrialization of this type of device for improving the development of modern processing and manufacturing of great strategic significance. The design and optimization of large-scales heavy gantry CNC Machining Center was mainly investigated in this paper. The finite element model of the beam structure was structured by using finite element analysis software-ANSYS. On the basis of analysis results, the optimal static and dynamic performance of square cross-section of the beam structure has been obtained. The maximal displacement is 0.531 mm. The maximum displacement of X=0.0329mm, and Y=0.531 mm occurred in the contact point of middle beam and spindle box. Z is 0.0948mm. The maximal displacement of Y-component is occurred in the contact points of guide and spindle box. This may have a certain impact on the machine processing accuracy. In the middle of the beam can consider to strengthen its internal structure, such as adding reinforcement measures to further improve its rigidity, and improve the machining precision of the whole machine.

scholarly journals Experimental and Numerical Analysis of Stainless Steel Microtube in Flaring Process

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Tsung-Chia Chen ◽  
Wei-Kai Ceng
Keyword(s):  
Finite Element ◽  
Cone Angle ◽  
Experimental Result ◽  
Flow Rule ◽  
Forming Process ◽  
Element Analysis ◽  
Punch Load ◽  
The Coefficient Of Friction ◽  
Updated Lagrangian ◽  
The Relationship

This study, with experiments and comparisons, aims to analyze the difference of stainless (SUS316L) microtubes in the flaring forming among dies with various semicone angles (35°, 40°, 45°, 50°, and 55°). The flow rule by Prandtl-Reuss combined with the finite element deformation theory and updated Lagrangian formulation (ULF) is applied to establish the finite element analysis equation for an incremental elastoplastic deformation to simulate the microtube flaring process. The broadrminalgorithm is utilized in the forming process for the elastoplastic state and die contact. The simulation data allow acquiring the deformation traceability, the relationship between punch load and punch stroke, the distribution of stress and strain, the distribution of the thinnest thickness resulted from dies with different semicone angles, and the distribution of flaring radius caused by dies with distinct semicone angles in the forming process. The experimental result presents similar results to the relationship between punch load and punch stroke and the simulation of the coefficient of frictionμ=0.05, revealing the analysis being suitable for the analysis of microtube cone angle flaring process. The analysis and experimental results show that the thinnest thickness of the microtube increases with increasing semicone angles of dies and the maximal flaring radius of microtubes increases with increasing semicone angles of dies.

scholarly journals Hot Forming Process Analysis of Ti6Al-4V Alloy: Experiment, Behaviour Modelling and Finite Element Simulation

2016 ◽  
Vol 838-839 ◽  
pp. 183-189 ◽  
Author(s):  
Vincent Velay ◽  
Hiroaki Matsumoto ◽  
Vanessa Vidal ◽  
Luc Penazzi ◽  
Fabien Nazaret ◽  
...  
Keyword(s):  
Finite Element ◽  
Process Analysis ◽  
Hot Forming ◽  
Strain Rates ◽  
Micro Structure ◽  
Forming Process ◽  
Identification Procedure ◽  
Element Simulation ◽  
Deforma Tion ◽  
Finite Element Calculations

The present investigation aims at evaluating and understanding the thermo-mechanical be-haviour of a titanium alloy under hot forming conditions. In this work, several considerations are ad-dressed. First, Scanning Electron Microscopy observations are performed to assess the evolutions of(α − β) phases, grain size, defects regarding the thermo-mechanical loadings from different static anddynamic tests (various temperatures and strain rates). Hence, the relationships between mechanicalproperties and micro-structure evolutions in such conditions allow a first assessment of the deforma-tion mechanisms in link with the macroscopic stress-strain curves. Afterwards, a behaviour modelformulation associated to an identification procedure of the parameters of the constitutive equationsis proposed. Finally, several tests performed under hot forming conditions and conducted on an in-dustrial press are compared to Finite Element calculations. Results are compared and provide someinteresting improvement ways in order to investigate the influence of the process parameters on thefinal shape of the part.

Experimental and Numerical Analysis of Titanium Alloy Microtube Tube-End Nosing Forming

2018 ◽  
Vol 920 ◽  
pp. 16-21
Author(s):  
Chien Yi Chen ◽  
Tsung Chia Chen
Keyword(s):  
Finite Element ◽  
Titanium Alloy ◽  
Friction Coefficient ◽  
Cone Angle ◽  
Contact Problems ◽  
Plastic State ◽  
Flow Rule ◽  
Forming Process ◽  
Element Analysis ◽  
Updated Lagrangian

This study is mainly based on five sets of mold cone angle and friction coefficient of micro-tube tube end necking forming analysis, and the tool cone angle of 60° experimental verification is carried out to analyze the titanium alloy (Grade 1) micro-tube for different mold cone angle and the different friction coefficient caused by the difference between the shrinkage forming. In this paper, Prandtl-Reuss's plastic flow rule, combined with finite element deformation theory and updated Lagrangian formulation (ULF) concept, establish an incremental elasto-plastic finite element analysis program for simulating the miniature tube end necking. The forming process also uses the generalized rmin algorithm to deal with elasto-plastic state and contact problems. From the simulation data of necking process, deformation history, punch load and punch stroke, stress and strain distribution is obtained. The analysis results show that by increasing the mold cone angle and friction coefficient, the thickness tends to be thicker in the certain area.

An Elasto-Plastic Finite Element Simulation of the UO-Tube Processes of Sheet Metal

2007 ◽  
Vol 340-341 ◽  
pp. 341-346
Author(s):  
Tsung Chia Chen ◽  
You Min Huang
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Moving Boundary ◽  
Contact Problems ◽  
Computer Code ◽  
Plastic State ◽  
Process Conditions ◽  
Forming Process ◽  
Moving Boundary Condition ◽  
Updated Lagrangian

This study aims to clarify the process conditions of the UO-tube of a sheet metal of steel. It provides a model that predicts not only the correct punch load for drawing, but also the precise final shape of products after unloading, based on the tensile properties of the material and the geometry of the tools used. An elasto-plastic incremental finite-element computer code, based on an updated Lagrangian formulation, was developed to simulate the UO-tube process of sheet metal; the results are compared with corresponding experimental results. Special care was taken to formulate accurate boundary conditions of penetration, separation and alternation of the sliding-sticking state of friction, as the contact conditions between the tools and the sheet varied throughout the entire processes of U-bending and successive O-bending. Calculated sheet geometries and forming force agree well with experimental data. In particular, selective reduced integration was adopted to formulate the stiffness matrix. The extended r-minimum technique was used to deal with the elasto-plastic state and contact problems at the tool-metal interface. A series of simulations were performed to validate the formulation in the theory, leading to the development of the computer codes. The whole deformation history, the distribution of stress and the distribution of strain during the forming process were obtained by carefully considering the moving boundary condition in the finite-element method. The simulation demonstrates clearly the efficiency of the code to simulate various bending processes that proceed under complicated deformation- and contact-history.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Sign in / Sign up

Export Citation Format

Share Document