Modeling and Simulation of Metal Forming Processes by XFEM

2016 ◽  
Vol 829 ◽  
pp. 41-45 ◽  
Author(s):  
Amit S. Shedbale ◽  
A.K. Sharma ◽  
Indra Vir Singh ◽  
B.K. Mishra
Keyword(s):  
Metal Forming ◽  
Yield Criterion ◽  
Isotropic Hardening ◽  
Plastic Behavior ◽  
Extended Finite Element ◽  
Material Interfaces ◽  
Updated Lagrangian Formulation ◽  
Von Mises ◽  
Updated Lagrangian ◽  
Level Set Approach

In this work, 2-D/3-D forming problems (extrusion and deep drawing) are numerically simulated by extended finite element method (XFEM). The updated Lagrangian formulation is used to model the large deformation. The von-Mises yield criterion is used to model the elasto-plastic behavior assuming isotropic hardening. Penalty approach is employed to impose the contact constraints and non–penetration condition at the material interfaces. The level set approach is used for locating the material interfaces. The numerical simulations of two forming problems are presented using developed nonlinear XFEM code.

Study of Material Modeling Strategies for Deformability Analysis of Rectangular Cups

2012 ◽  
Vol 498 ◽  
pp. 243-248
Author(s):  
Hirpa G. Lemu ◽  
T. Trzepieciński
Keyword(s):  
Finite Element ◽  
Metal Forming ◽  
Yield Criterion ◽  
Material Modeling ◽  
Isotropic Hardening ◽  
Friction Anisotropy ◽  
Element Analysis ◽  
Forming Simulation ◽  
The Finite Element Analysis ◽  
Von Mises

A comparative study of different material modeling strategies in deformability analysis of rectangular cups is presented in this paper. The article focuses on application of dynamic explicit and static implicit approaches in Finite Element Methods (FEM) for metal forming simulation where different material models and contact conditions with friction are involved. The simulated results are verified using results from experimental study of the deformation on the same material. Further, a comparison between a quadratic Hill anisotropic yield criterion and von Mises yield criterion with isotropic hardening has been studied. The results confirm that the dynamic explicit method is more efficient in simulating sheet metal forming processes. The study shows also that the finite element analysis undoubtedly gives good approximate numerical results to real processes when the material and friction anisotropy are considered.

scholarly journals Elastic-plastic analysis of metallic shells at finite strains

2007 ◽  
Vol 60 (2) ◽  
pp. 381-389 ◽  
Author(s):  
Eduardo Moraes Barreto Campello ◽  
Paulo de Mattos Pimenta ◽  
Peter Wriggers
Keyword(s):  
Finite Strain ◽  
Yield Criterion ◽  
Isotropic Hardening ◽  
Triangular Finite Element ◽  
Numerical Examples ◽  
Plastic Analysis ◽  
Isotropic Elasticity ◽  
Von Mises ◽  
Variable Thickness Shell ◽  
Thickness Shell

The geometrically-exact finite-strain variable-thickness shell model of [1] is reviewed in this paper and extended to the case of metallic elastoplastic shells. Isotropic elasticity and von Mises yield criterion with isotropic hardening are considered. The model is implemented within a triangular finite element and is briefly assessed by means of two numerical examples.

An Analytical Elastic-Plastic Contact Model

2011 ◽  
Author(s):  
M. R. Brake
Keyword(s):  
Yield Criterion ◽  
Plastic Behavior ◽  
Elastic Plastic ◽  
Elastic Regime ◽  
Plastic Regime ◽  
Elastic Process ◽  
New Formulation ◽  
Von Mises ◽  
The Impact ◽  
Force Displacement

This paper presents a new formulation for elastic-plastic contact in the normal direction between two round surfaces that is solely based on material properties and contact geometries. The problem is formulated as three separate domains: the elastic regime, mixed elastic-plastic behavior, and unconstrained (fully plastic) flow. Solutions for the force-displacement relationship in the elastic regime follow from Hertz’s classical solution. In the fully plastic regime, two assumptions are made: that there is a uniform pressure distribution and that there is conservation of volume. The force-displacement relationship in the intermediate, mixed elastic-plastic regime is approximated by enforcing continuity between the elastic and fully plastic regimes. Transitions between the three regimes are determined based on empirical quantities: the von Mises yield criterion is used to determine the initiation of mixed elastic-plastic deformation, and Brinell’s hardness for the onset of unconstrained flow. Unloading from each of these three regimes is modeled as an elastic process with different radii of curvature based on the regime in which the maximum force occurred. Simulation results explore the relationship between the impact velocity and coefficient of restitution. Further comparisons are made between the model, experimental results found in the literature, and other existing elastic-plastic models.

Finite Element Implementation of a Thermoviscoplastic Model for Ratcheting

2004 ◽  
Author(s):  
Rashid K. Abu Al-Rub ◽  
George Z. Voyiadjis
Keyword(s):  
Finite Element ◽  
Strain Rate ◽  
Yield Criterion ◽  
Isotropic Hardening ◽  
Strain Rate Effects ◽  
Finite Element Implementation ◽  
Rate Dependent ◽  
Proposed Model ◽  
Integration Algorithms ◽  
Von Mises

A thermoviscoplastic constitutive model is proposed to simulate the uniaxial/multiaxial ratcheting of cyclically stable materials and its finite element implementation is also achieved. The kinematic and isotropic hardening rules used in the proposed model are similar to that developed by Voyiadjis and Abu Al-Rub [1], except for the coupling with temperature and strain-rate effects. The proposed constitutive equations include thermo-elasto-viscoplasticity, a dynamic yield criterion of a von Mises type, the associated flow rules, non-linear strain hardening, strain-rate hardening, and temperature softening. In the finite element implementation of the proposed model new implicit stress integration algorithms are proposed. The proposed unified integration algorithms are extensions of the classical rate-independent radial return scheme to the rate-dependent problems. A new expression of consistent tangent modulus is also derived for rate- and temperature-dependent inelasticity. The proposed model is verified by simulating the uniaxial ratcheting of a metallic material.

Geometric and Material Nonlinear Analyses of a Heated Zigzag Pipeline: Case Study to Look for High Stress Situations

2006 ◽  
Author(s):  
Adilson Carvalho Benjamin ◽  
Rita de Ca´ssia Carvalho Silva ◽  
Joa˜o Nisan Correia Guerreiro ◽  
Abimael Fernando Dourado Loula
Keyword(s):  
Yield Criterion ◽  
High Stress ◽  
General Purpose ◽  
Isotropic Hardening ◽  
Plasticity Model ◽  
Nonlinear Analyses ◽  
Hardening Rule ◽  
Von Mises ◽  
Material Nonlinear

This paper describes the case study performed to look for high stress situations that may occur along the life span of a heated zigzag pipeline. The main results of several finite element (FE) analyses are presented. These analyses were performed using the general purpose FE program ABAQUS considering geometric and material nonlinearities. A rate-independent plasticity model using the von Mises yield criterion and isotropic hardening rule were adopted.

scholarly journals Application of a Dung’s Model to Predict Ductile Fracture of Aluminum Alloy Sheets Subjected to Deep Drawing

2015 ◽  
Vol 18 (2) ◽  
pp. 38-48
Author(s):  
Hao Nguyen-Huu ◽  
Trung N.Nguyen ◽  
Hoa Vu - Cong
Keyword(s):  
Aluminum Alloy ◽  
Deep Drawing ◽  
Void Nucleation ◽  
Yield Criterion ◽  
Matrix Material ◽  
Damage Model ◽  
Isotropic Hardening ◽  
Microscopic Damage ◽  
Von Mises ◽  
Hardening Rules

In this paper, prediction of failed evolution of anisotropic voided ductile materials will be developed based on Dung’s microscopic damage model. An isotropic and anisotropic formulation of the Dung’s damage model that using von Mises yield criterion and Hill’s quadratic anisotropic yield criterion (1948) integrated with isotropic hardening rules of matrix material used to simulate the deep drawing process of aluminum alloy sheets. The model is implemented as a vectorized user-defined material subroutine (VUMAT) in the ABAQUS/Explicit commercial finite element code. The predictions of ductile crack behavior in the specimens based on void nucleation, growth and coelescence are compared with Gurson – Tvergaard – Needleman (GTN) model and experiment results from reference.

Application of the Radial Return Method to Compute Stress Increments From Mroz’s Hardening Rule

2000 ◽  
Vol 123 (4) ◽  
pp. 398-402 ◽  
Author(s):  
Sing C. Tang ◽  
Z. Cedric Xia ◽  
Feng Ren
Keyword(s):  
Metal Forming ◽  
Computing Time ◽  
Isotropic Hardening ◽  
Stress Increment ◽  
Anisotropic Hardening ◽  
Forming Process ◽  
Shell Elements ◽  
Hardening Rule ◽  
Metal Forming Process ◽  
Return Method

It is well known in the literature that the isotropic hardening rule in plasticity is not realistic for handling plastic deformation in a simulation of a full sheet-metal forming process including springback. An anisotropic hardening rule proposed by Mroz is more realistic. For an accurate computation of the stress increment for a given strain increment by using Mroz’s rule, the conventional subinterval integration takes excessive computing time. This paper proposes the radial return method to compute such stress increment for saving computing time. Two numerical examples show the efficiency of the proposed method. Even for a sheet model with more than 10,000 thin shell elements, the radial return method takes only 40 percent of the overall computing time by the subinterval integration.

Meshless TL and UL Approaches for Large Deformation Analysis

2010 ◽  
Vol 139-141 ◽  
pp. 893-896 ◽  
Author(s):  
Yuan Tong Gu
Keyword(s):  
Large Deformation ◽  
Computational Efficiency ◽  
Metal Forming ◽  
Weak Form ◽  
Superior Performance ◽  
Deformation Analysis ◽  
Large Deformation Analysis ◽  
Updated Lagrangian ◽  
Local Weak Form ◽  
Large Deformation Problems

To accurately and effectively simulate large deformation is one of the major challenges in numerical modeling of metal forming. In this paper, an adaptive local meshless formulation based on the meshless shape functions and the local weak-form is developed for the large deformation analysis. Total Lagrangian (TL) and the Updated Lagrangian (UL) approaches are used and thoroughly compared each other in computational efficiency and accuracy. It has been found that the developed meshless technique provides a superior performance to the conventional FEM in dealing with large deformation problems for metal forming. In addition, the TL has better computational efficiency than the UL. However, the adaptive analysis is much more efficient using in the UL approach than using in the TL approach.

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