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.

Computer Aided Modeling of Deep-Drawing

2007 ◽  
Vol 344 ◽  
pp. 341-348
Author(s):  
Mehmet Ali Pişkin ◽  
Bilgin Kaftanoğlu
Keyword(s):  
Finite Element ◽  
Deep Drawing ◽  
Plastic Material ◽  
Yield Criterion ◽  
Shell Element ◽  
Material Model ◽  
Industrial Applications ◽  
Finite Element Program ◽  
Element Program ◽  
Von Mises

Deep-drawing operations are performed widely in industrial applications. It is very important for efficiency to achieve parts with no defects. In this work, a finite element method is developed to simulate deep-drawing operation including wrinkling. A four nodded five degree of freedom shell element is formulated. Isotropic elasto-plastic material model with Von Mises yield criterion is used. By using this shell element, the developed code can predict the bending behavior of workpiece besides membrane behavior. Simulations are carried out with four different element sizes. The thickness strain and nodal displacement values obtained are compared with results of a commercial finite element program and results of previously conducted experiments.

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.

scholarly journals Anisotropic Deformation Behavior of Al2024T351 Aluminum Alloy

2013 ◽  
Vol 10 (1) ◽  
pp. 80 ◽  
Author(s):  
R Khan
Keyword(s):  
Aluminum Alloy ◽  
Yield Strength ◽  
Deformation Behavior ◽  
Yield Criterion ◽  
Tensile Tests ◽  
Rolled Plate ◽  
Uniaxial Tensile ◽  
Element Analysis ◽  
Yield Criteria ◽  
Von Mises

 The objective of this work was to investigate the effects of material anisotropy on the yielding and hardening behavior of 2024T351 aluminum alloy using isotropic and anisotropic yield criteria. Anisotropy may be induced in a material during the manufacturing through processes like rolling or forging. This induced anisotropy gives rise to the concept of orientation-dependent material properties such as yield strength, ductility, strain hardening, fracture strength, or fatigue resistance. Inclusion of the effects of anisotropy is essential in correctly predicting the deformation behavior of a material. In this study, uniaxial tensile tests were first performed in all three rolling directions, L , T  and S , for smooth bar specimens made from hot rolled plate of Al2024 alloy. The experimental results showed that the L - and T -directions yielded higher yield strengths and a greater percentage of elongation before fracture than the S -direction. Subsequently, finite element analysis of tensile specimens was performed using isotropic (von Mises) and anisotropic (Hill) yield criteria to predict the onset of yielding and hardening behaviors during the course of deformation. Hill's criterion perfectly fitted with the test data in the S -direction, but slightly underestimated the yield strength in L -direction. The results indicated that the Hill yield criterion is the most suitable one to predict the onset of yielding and hardening behaviors for 2024T351 aluminum alloy in all directions. 

Plane-Strain Tension Tests on Aluminum Alloy Sheet

1995 ◽  
Vol 117 (2) ◽  
pp. 168-171 ◽  
Author(s):  
Fadi Taha ◽  
Alejandro Graf ◽  
William Hosford
Keyword(s):  
Aluminum Alloy ◽  
Plane Strain ◽  
Yield Criterion ◽  
Alloy Sheet ◽  
Isotropic Hardening ◽  
Aluminum Alloy Sheet ◽  
Strain Measurements ◽  
Plane Strain Tension ◽  
Tension Tests ◽  
High Exponent

A simple way of making plane-strain tension tests on sheet specimens has been developed. This method was used to test sheets of aluminum alloy 2008 T4 and the results were analyzed in terms of a high exponent yield criterion and isotropic hardening. Experimentally measured forces agreed with those calculated from strain measurements using uniaxial tension test curves.

scholarly journals Implementation and application of Dung’s model to analyze ductile fracture of metallic material

2015 ◽  
Vol 18 (2) ◽  
pp. 139-148
Author(s):  
Hao Nguyen Huu ◽  
Trung N. Nguyen ◽  
Hoa Vu Cong
Keyword(s):  
Volume Fraction ◽  
Void Nucleation ◽  
Damage Model ◽  
Equivalent Plastic Strain ◽  
High Strength ◽  
Ductile Fractures ◽  
Final Failure ◽  
Microscopic Damage ◽  
Ductile Behavior ◽  
Tension Loading

In this paper, the Dung’s microscopic damage model which depicts void growth under plastic deformation is applied to predict ductile fractures in high strength steel API X65. The model is implemented as a vectorized userdefined material subroutine (VUMAT) in the ABAQUS/Explicit commercial finite element code. Notched and smooth round bars under uniaxial tension loading are simulated to show the effect of equivalent plastic strain versus the void volume fraction growth of the material at and after crack initiation. Predictions of the ductile behavior from void nucleation to final failure stage are compared with the built-in Gurson – Tvergaard – Needleman (GTN) model in ABAQUS. Also, comparison with experimental results from the literature is discussed.

scholarly journals A large strain gradient-enhanced ductile damage model: finite element formulation, experiment and parameter identification

2020 ◽  
Vol 231 (12) ◽  
pp. 5159-5192
Author(s):  
L. Sprave ◽  
A. Menzel
Keyword(s):  
Parameter Identification ◽  
Yield Criterion ◽  
Damage Model ◽  
Image Correlation ◽  
Ductile Damage ◽  
Isotropic Hardening ◽  
Surface Model ◽  
Element Formulation ◽  
Tensile Experiment ◽  
Von Mises Plasticity

Abstract A gradient-enhanced ductile damage model at finite strains is presented, and its parameters are identified so as to match the behaviour of DP800. Within the micromorphic framework, a multi-surface model coupling isotropic Lemaitre-type damage to von Mises plasticity with nonlinear isotropic hardening is developed. In analogy to the effective stress entering the yield criterion, an effective damage driving force—increasing with increasing plastic strains—entering the damage dissipation potential is proposed. After an outline of the basic model properties, the setup of the (micro)tensile experiment is discussed and the importance of including unloading for a parameter identification with a material model including damage is emphasised. Optimal parameters, based on an objective function including measured forces and the displacement field obtained from digital image correlation, are identified. The response of the proposed model is compared to a tensile experiment of a specimen with a different geometry as a first approach to validate the identified parameters.

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.

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.

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