skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Comparisons of FEM Approaches Modelling the Metal Plastic Behaviour

Abstract

Simple phenomenological laws (e.g. classical Hill 1948 quadratic law) are compared to more complex laws based on crystal plasticity through various numerical simulations: mechanical tests of ECAE materials, nanoindentation of titanium alloys and copper, and large strain torsion of copper bars. Taking into consideration the complexity of the investigated processes, the numerical results present rather good agreements with experimental observations.

Authors:
; ; ;  [1]
  1. ArGEnCo Department, MS2F Division, ULg, Chemin des Chevreuils 1, 4000 Liege (Belgium)
Publication Date:
OSTI Identifier:
21056999
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 907; Journal Issue: 1; Conference: 10. ESAFORM conference on material forming, Zaragoza (Spain), 18-20 Apr 2007; Other Information: DOI: 10.1063/1.2729724; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; COPPER; COPPER ALLOYS; CRYSTALS; FINITE ELEMENT METHOD; MECHANICAL TESTS; PLASTICITY; STRAINS; TITANIUM ALLOYS; TORSION

Citation Formats

Habraken, A. M., Gerday, A. F., Diouf, B., and Duchene, L. Comparisons of FEM Approaches Modelling the Metal Plastic Behaviour. United States: N. p., 2007. Web. doi:10.1063/1.2729724.
Habraken, A. M., Gerday, A. F., Diouf, B., & Duchene, L. Comparisons of FEM Approaches Modelling the Metal Plastic Behaviour. United States. doi:10.1063/1.2729724.
Habraken, A. M., Gerday, A. F., Diouf, B., and Duchene, L. Sat . "Comparisons of FEM Approaches Modelling the Metal Plastic Behaviour". United States. doi:10.1063/1.2729724.
@article{osti_21056999,
title = {Comparisons of FEM Approaches Modelling the Metal Plastic Behaviour},
author = {Habraken, A. M. and Gerday, A. F. and Diouf, B. and Duchene, L.},
abstractNote = {Simple phenomenological laws (e.g. classical Hill 1948 quadratic law) are compared to more complex laws based on crystal plasticity through various numerical simulations: mechanical tests of ECAE materials, nanoindentation of titanium alloys and copper, and large strain torsion of copper bars. Taking into consideration the complexity of the investigated processes, the numerical results present rather good agreements with experimental observations.},
doi = {10.1063/1.2729724},
journal = {AIP Conference Proceedings},
number = 1,
volume = 907,
place = {United States},
year = {Sat Apr 07 00:00:00 EDT 2007},
month = {Sat Apr 07 00:00:00 EDT 2007}
}
  • The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parametersmore » to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.« less
  • Strain recovery after removal of forming loads, commonly defined as springback, is of great concern in sheet metal forming, in particular with regard to proper prediction of the final shape of the part. To control the problem a lot of work has been done, either by minimizing the springback on the material side or by increasing the estimation precision in corresponding process simulations. Unfortunately, by currently available software springback still cannot be adequately predicted, because most analyses of springback are using linear, isotropic and constant Young's modulus and Poisson's ratio. But, as it was measured and reported, none of itmore » is true. The aim of this work is to propose an upgraded mechanical model which takes evolution of damage and related orthotropic stiffness degradation into account. Damage is considered by inclusion of ellipsoidal cavities, and their influence on the stiffness degradation is taken in accordance with the Mori-Tanaka theory, adopting the GTN model for plastic flow. With regard to the case in which damage in material is neglected it is shown in the article how the springback of a formed part differs, when we take orthotropic damage evolution into consideration.« less
  • To model the idealized exciting current sources, such as the ideal line current and ideal current sheet, in the FEM, a general approach is proposed in this paper. The idealized exciting current sources are represented by means of the Dirac Delta function. Some numerical examples will show the good accuracy of the developed method.
  • The conservation equations of a coupled thermomechanical - solute transport model to be applied in mushy zones are first recalled. Then the numerical implementation is discussed, in the context of steel continuous casting modeling. Application to the study of the end of solidification is then considered and the effects of soft reduction process are discussed.
  • There are enormous heterogeneous interfaces in the interior of metal matrix composites (MMCs). Because of the significant difference between the coefficients of thermal expansion (CTEs) of the matrix and reinforcement, the complicated thermal residual stresses are believed to be induced into the matrix and reinforcement near the interfaces when composites are fabricated or annealed at a certain high temperature and cooled down to room temperature. In order to obtain a further understanding of the thermal residual stress distribution near the interfaces in such a material, the residual stress distribution along the depth in 6061 Al component of bonded SiC/6061 Almore » model material was determined by X-ray stress measurement. Meanwhile, FEM was performed to analyze the residual stress distribution in the two constituents and the results were discussed. In the bonded SiC/6061 Al model material, the residual stress distribution is nearly linear in SiC component, and non-linear in the 6061 Al part. The calculated results indicate that the residual stress state in the components depends on the ratio of the thickness of ceramic and metal. The measured and calculated residual stress distributions are in agreement in general trend, however the calculated values are higher than the measured ones.« less