Damage prediction in incremental forming by using Lemaitre damage model

2012 ◽  
Author(s):  
Shenghua Wu ◽  
Ana Reis ◽  
Pedro Teixeira ◽  
A. Barata da Rocha ◽  
Jorge Lino
Keyword(s):  
Incremental Forming ◽  
Damage Model ◽  
Damage Prediction ◽  
Lemaitre Damage Model

IMPLEMENTATION OF THE LEMAITER DAMAGE MODEL IN ANSYS FINITE ELEMENT COMPLEX

2020 ◽  
pp. 30-48
Author(s):  
D.A. Kosov ◽  
◽  
D.I. Fedorenkov ◽  
A.V. Tumanov ◽  
◽  
...  
Keyword(s):  
Finite Element ◽  
Numerical Experiment ◽  
Numerical Experiments ◽  
Damage Accumulation ◽  
Cylindrical Specimen ◽  
Damage Model ◽  
Finite Element Calculation ◽  
Element Calculation ◽  
Lemaitre Damage Model ◽  
Calculation Software

In this work, the simplified Lemaitre damage model was integrated into the ANSYS finite element calculation software. The model is implemented as a dynamically linked library of custom material for 2D problems. The model was tested on a cylindrical specimen with an annular cut. The stages of damage accumulation in the numerical experiment coincide with similar numerical experiments known in the literature.

Determination of Flow Curve Using Bulge Test and Calibration of Damage for Ito-Goya Models

2013 ◽  
Vol 554-557 ◽  
pp. 182-189 ◽  
Author(s):  
Bruno Martins ◽  
Abel D. Santos ◽  
Pedro Teixeira ◽  
K. Ito ◽  
N. Mori
Keyword(s):  
Tensile Test ◽  
Damage Model ◽  
Strain Curve ◽  
Uniaxial Tensile ◽  
Bulge Test ◽  
Uniaxial Tensile Test ◽  
Damage Prediction ◽  
Damage Models ◽  
Material Information

The standard uniaxial tensile test is the widely accepted method to obtain relevant properties of mechanical characterization of sheet metal materials. However the range of strain obtained from tensile test is limited. The bulge test is an alternative to obtain ranges of deformation, higher than tensile test, thus permitting a better characterization for material behaviour. This paper presents a sensitivity analysis for some influencing variables used in bulge measurements, thus giving some guidelines for the evaluation of the stress-strain curve from experimental results using a developed experimental mechanical system. Additionally, using bulge test up to fracture shall give material information regarding damage, which in turn may be used to evaluate and calibrate damage models. A methodology is presented to be used for evaluation and calibration of Ito-Goya damage model of damage prediction.

Enhanced CDM model accounting of stress triaxiality and Lode angle for ductile damage prediction in metal forming

2020 ◽  
pp. 105678952095804
Author(s):  
Kai Zhang ◽  
Houssem Badreddine ◽  
Naila Hfaiedh ◽  
Khemais Saanouni ◽  
Jianlin Liu
Keyword(s):  
Constitutive Equations ◽  
Damage Model ◽  
Stress Triaxiality ◽  
Ductile Damage ◽  
Irreversible Processes ◽  
State Variables ◽  
Damage Prediction ◽  
Proposed Model ◽  
Lode Angle ◽  
Fully Coupled

This paper deals with the prediction of ductile damage based on CDM approach fully coupled with advanced elastoplastic constitutive equations. This fully coupled damage model is developed based on the total energy equivalence assumption under the thermodynamics of irreversible processes framework with state variables. In this model, the damage evolution is enhanced by accounting for both stress triaxiality and Lode angle. The proposed constitutive equations are implemented into Finite Element (FE) code ABAQUS/Explicit through a user material subroutine (VUMAT). The material parameters are determined by the hybrid experimental-numerical method using various tensile and shear tests. Validation of the proposed model has been done using different tests of two aluminum alloys (Al6061-T6 and Al6014-T4). Through comparisons of numerical simulations with experimental results for different loading paths, the predictive capabilities of the proposed model have been shown. The model is found to be able to capture the initiation as well as propagation of macro-crack in sheet and bulk metals during their forming processes.

Assessment of Damage Models in Sheet Metal Forming for Industrial Applications

2011 ◽  
Vol 473 ◽  
pp. 482-489
Author(s):  
Maria Doig ◽  
Karl Roll
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Damage Model ◽  
High Strength ◽  
Industrial Applications ◽  
Production Costs ◽  
Model Parameters ◽  
Damage Prediction ◽  
Damage Models

Due to increasing demands to reduce C02-emission and to augment occupant’s safety new modern materials are developed ongoing. Because of relatively low production costs, high strength and simultaneously good formability the advanced high strength steels (AHSS) are applied among others for the lightweight design of body-in-white components in the automotive industry. Their already mentioned properties follow from the presence of mixed mild and hard ferrous phases. Due to this multiphase microstructure of the most AHSS steels, a complex material and damage behavior is observed during forming. The damage grows in a ductile manner during plastic flow and the cracks appear without necking. They are often characterized as the so called shear cracks. The damage predictions with standard methods like the forming limit curve (FLC) lack accuracy and reliability. These methods are based on the measurement of linear strain paths. On the other hand ductile damage models are generally used in the bulk forming and crash analysis. The goal is to prove if these models can be applied for the damage prediction in sheet metal forming and which troubles have to be overcome. This paper demonstrates the capability of the Gurson-Tvergaard-Needleman (GTN) model within commercial codes to treat industrial applications. The GTN damage model describes the existence of voids and they evolution (nucleation, growth and coalescence). After a short introduction of the model the finite element aspects of the simulative damage prediction have been investigated. Finally, the determination of the damage model parameters is discussed for a test part.

Efficient pseudo-inverse approach for damage prediction in cold forging process simulation

2014 ◽  
Vol 23 (8) ◽  
pp. 1168-1188 ◽  
Author(s):  
Ali Halouani ◽  
Yuming Li ◽  
Boussad Abbès ◽  
Ying-Qiao Guo
Keyword(s):  
Process Simulation ◽  
Large Strain ◽  
Damage Model ◽  
Cold Forging ◽  
Integration Algorithm ◽  
Damage Prediction ◽  
Forging Process ◽  
Inverse Approach ◽  
Pseudo Inverse ◽  
Flow Theory Of Plasticity

This article presents an efficient pseudo-inverse approach for the damage prediction in cold forging process simulation. Pseudo-inverse approach combines the advantages of the fast inverse approach and accurate incremental approaches. Some intermediate configurations are created geometrically and corrected mechanically to well describe the deformation path. The formulation of an axi-symmetrical element based on pseudo-inverse approach is presented. A strain-based damage model is introduced in the flow theory of plasticity. A direct scalar integration algorithm of plasticity-damage is developed, leading to a fast and robust algorithm for large strain increments. The cold forging processes of two axi-symmetrical parts are simulated to validate pseudo-inverse approach by the incremental approach ABAQUS/Explicit. Pseudo-inverse approach gives very good results, but uses much less CPU time.

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