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doc:user:general:glossaire [2017/10/25 10:25] bomandoc:user:general:glossaire [2017/10/25 11:51] (current) boman
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 ~~NOTOC~~ ~~NOTOC~~
 If you have never used a finite element software, nor learned about nonlinear mechanics, this page will help you understand Metafor specific vocabulary. If you have never used a finite element software, nor learned about nonlinear mechanics, this page will help you understand Metafor specific vocabulary.
 +
 +
 +----
 +
  
 ===== A ===== ===== A =====
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 ==== Abaqus ==== ==== Abaqus ====
  
-{{ doc:user:abaqus-6-6.jpg?100|doc:user:abaqus-6-6.jpg}} 
 Commercial software suite for finite element analysis, usually considered as the reference in nonlinear mechanics. [[#Metafor]] deals with similar mechanical problems as [[wp>ABAQUS]]. Commercial software suite for finite element analysis, usually considered as the reference in nonlinear mechanics. [[#Metafor]] deals with similar mechanical problems as [[wp>ABAQUS]].
  
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 ==== Battery ==== ==== Battery ====
  
-Also called the "test battery"The "battery" is actually a test suite made of all the input files that are checked for each new version of [[#Metafor]].+Also called the "test battery"It is actually a **test suite** made of more than 2000 input files that are checked for each new version of [[#Metafor]]. It is also an interesting source of examples for people who want to learn how to use Metafor. The main folder of the battery is ''apps''.
  
 ==== Bfac ==== ==== Bfac ====
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 ==== C++ ==== ==== C++ ====
-{{doc:user:bjarne-stroustrup.jpg?80 |doc:user:bjarne-stroustrup.jpg}}+{{ doc:user:bjarne-stroustrup.jpg?80|doc:user:bjarne-stroustrup.jpg}}
 [[#Object-oriented]] programming language used to develop [[#Metafor]]. See also [[wp>C++]]. [[#Object-oriented]] programming language used to develop [[#Metafor]]. See also [[wp>C++]].
- 
-==== CAD ==== 
-{{doc:user:modell-cad.jpg?200 |doc:user:modell-cad.jpg}} 
-[[wp>Computer-aided_design|Computer Aided Design]]. By extension, the CAD of a test case is its geometry. 
- 
-==== Code de calcul ==== 
- 
-Autre manière d'appeler un logiciel qui bouffe du CPU. 
  
 ==== Contact ==== ==== Contact ====
  
-Interaction between two solids which models the fact that they cannot penetrate each other during the computation. Contact induces nonlinearities in the computation. The penalty method is most often used in [[#Metafor]]. To handle contact, [[#Metafor]] creates contacts [[#fe|éléments]] on each node that can be in contact with, either, another deformable solid (defo-defo contact), or a [[#Contact Matrices|rigid contact matrix]] (also called die, rigid-defo contact).+Interaction between two solids which models the fact that they cannot penetrate each other during the computation. Contact induces nonlinearities in the computation. The penalty method is most often used in [[#Metafor]]. To handle contact, [[#Metafor]] creates contacts [[#fe|elements]] on each node that can be in contact with, either, another deformable solid (defo-defo contact), or a [[#Contact Matrices|rigid contact tool]] (rigid-defo contact).
  
 ==== Contact Matrices ==== ==== Contact Matrices ====
  
-Also called "dies" in Metal Forming. A contact matrix is a rigid geometric object (cylindrical, plane or of more complex shape) which can come into contact with the meshed part. For instance, a roll and a drawing punch may be modeled by one or more contact matrices.+Also called "contact tools" in metal forming. A contact matrix is a perfectly rigid geometric object (a cylinderplane, ...) which can come into contact with a mesh. For instance, a drawing punch or a blankholder may be modeled by contact matrix.
  
 ==== Curves ==== ==== Curves ====
  
-When used on its own, the word "curve" must be understood as "temporal result curve", which is a series of values extracted from the simulation at each time step, then saved in a ''.ascii'' file (usable in Matlab). For example, [[#Metafor]] can plot contact forces over time, plastic strains in a section, punctual temperature ...+When used on its own, the word "curve" must be understood as "history curve", which is a series of values extracted from the simulation at each time step, then saved in a text file with a ''.ascii'' extension. For example, [[#Metafor]] can build curves for contact forces over time, plastic strains in a section, nodal temperatures, ...
  
-===== D ===== 
  
-==== Data set ====+---- 
 + 
 + 
 +===== D =====
  
-Text file describing the geometry, mesh, boundary conditions and temporal integration parameters of a simulation. In [[#Metafor]], a data set is a series of commands gathered in a [[#module]] and interpreted by [[#Python]]. 
  
 ==== DLL ==== ==== DLL ====
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 [[#Metafor]] is made of around 20 libraries on Windows. It also depends on other librarires, such as [[#VTK]], Qt ou les BLAS. On Unix, Metafor has not yet been split into DLLs.  [[#Metafor]] is made of around 20 libraries on Windows. It also depends on other librarires, such as [[#VTK]], Qt ou les BLAS. On Unix, Metafor has not yet been split into DLLs. 
  
 +
 +----
  
  
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 Finite Element. See also [[Wp>Finite_element]]. Finite Element. See also [[Wp>Finite_element]].
  
-In [[#Metafor]], elements are objects that compute forces and send them back to the integration algorithm. +In [[#Metafor]], elements are objects that compute forces and send them back to the time integration algorithm. 
  
 ==== FEM ==== ==== FEM ====
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 ==== Fortran ==== ==== Fortran ====
  
-Obsolete language still used by the elderly. +Obsolete programming language still used by many commercial finite element codes.
- +
-==== Franglais ==== +
- +
-Langue utilisée entre autres par [[#Metafor]] (voir [[#BFac]] par exemple) malgré nos efforts pour l'éviter.+
  
 ==== FV ==== ==== FV ====
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 Finite Volume. Alternative discretization technique, in opposition with Finite Element. Finite Volumes are used to model convection with the [[#ALE]] formulation. Finite Volume. Alternative discretization technique, in opposition with Finite Element. Finite Volumes are used to model convection with the [[#ALE]] formulation.
  
-===== G ===== 
  
 +----
  
-==== GPL ==== 
- 
-[[wp>GNU Public License]] : most widely used free software license, see [[http://www.gnu.org/copyleft/gpl.html|site GNU]]. [[#Metafor]] license is unfortunately not GPL. 
  
 ===== I ===== ===== I =====
 +
 +==== Input file ====
 +
 +Text file describing the geometry, mesh, boundary conditions and time integration parameters of a simulation. In [[#Metafor]], an input file is a series of [[#Python]] commands gathered in a [[#module]].
 +
  
 ==== Interaction ==== ==== Interaction ====
  
-At first, an interaction was the object managing the boundary condition [[#fe|éléments]] on the surface of a mesh (contact, pressure). Nowadays, this concept has been extended to the generation of any [[#fe|finite element]], even [[#Volume Element]].+At first, an interaction was the object managing the boundary condition [[#fe|elements]] on the surface of a mesh (contact, pressure). Nowadays, this concept has been extended to the generation of any [[#fe|finite element]], even [[#Volume Element]].
  
 ==== Interpreter ==== ==== Interpreter ====
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 ==== Iterations ==== ==== Iterations ====
  
-On its own, iteration means mechanical iteration of the [[#Newton-Raphson]] algorithm, used at each time step to converge to the right solution.+On its own, iteration means mechanical iteration of the [[#Newton-Raphson]] algorithm, used at each time step to converge to an equilibrated solution. 
 + 
 + 
 +---- 
  
 ===== J ===== ===== J =====
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 ==== Jacobian ==== ==== Jacobian ====
  
-The jacobian of a [[#fe|element]] characterizes the factor by which the volume of this element expands or shrinks between a given configuration and the reference one. It is always positive, unless the element orientation was reversed, in which case the computation cannot continue further.+The jacobian of a [[#fe|element]] characterizes the factor by which the volume of this element expands or shrinks between a given configuration and the reference one. It is always positive, unless the element orientation was inverted or distorted, in which case the computation cannot continue further.
  
-===== L ===== 
  
-==== LGPL ====+----
  
-License derived from [[#GPL]] (Lesser GPL), usually used for libraries, allowing the developer to use LGPL without having to make its code GPL. Consequently, a commercial software may use LGPL libraries. See [[http://www.gnu.org/copyleft/lgpl.html|site GNU]]. For example, [[#Metafor]] uses [[http://libnurbs.sourceforge.net/|Nurbs++]], which is LGPL. 
  
 ===== M ===== ===== M =====
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 ==== Machine ==== ==== Machine ====
  
-Dans le contexte de ce siteune machine n'est pas une perceuse ni un une scie électrique mais plutôt un PC ou, à la rigueur, la machine à café.+In the context of this websitea "machine" is neither a power saw nor a pneumatic drill but rather a PC or sometimes a coffee machine.
  
  
 ==== Material ==== ==== Material ====
  
-A material defines the evolution of stresses with respect to strains. By extension, contact material is the name used when talking about friction laws.+A material is the implementation of a constitutive law which defines the evolution of stresses with respect to strains. By extension, contact material is the name used when talking about friction laws.
  
 ==== Memory leak ==== ==== Memory leak ====
  
 Quite often seen when programming with an [[#object-oriented]] language. It is due to allocated memory which is never freed. So solve this, destructors can be programmed or more RAM bought. Quite often seen when programming with an [[#object-oriented]] language. It is due to allocated memory which is never freed. So solve this, destructors can be programmed or more RAM bought.
- 
-==== Mesh ==== 
- 
-In [[#Metafor]], the mesh geometry is simply called mesh, in opposition with the user geometry, which is the one encoded by the user in its [[#data set]]. 
  
 ==== Mesh element ==== ==== Mesh element ====
  
-In [[#Metafor]], a mesh element is the geometric part of a [[#fe|finite element]]. A mesh element can be quadrangular, triangular, ... Mesh elements are created by meshers. The user applies finite elements on mesh elements through [[#interaction|interactions]].+In [[#Metafor]], a mesh element is the geometric part of a [[#fe|finite element]]. A mesh element can be quadrangular, triangular, ... Mesh elements are created by meshers. The user creates finite elements on mesh elements through [[#interaction|interactions]].
  
 ==== Metafor ==== ==== Metafor ====
  
-Thermo-mechanical [[#fe|Finite Element]] software developed in the LTAS-MN2L, taking large strains of solids into account. Initially started by J.-P. Ponthot, Metafor has grown and now gathers the contributions from all scientists in the laboratory. it is also used on a commercial way by [[http://www.gdtech.net/|GDTech]].+Thermo-mechanical [[#fe|Finite Element]] software developed in the LTAS-MN2L, taking large strains of solids into account. Initially started by J.-P. Ponthot, Metafor has become bigger and bigger and now gathers the contributions from all researchers in the laboratory. It is also used on a commercial way by [[http://www.gdtech.eu/|GDTech]], [[http://www.crmgroup.be/|CRM]] and [[https://www.safran-aero-boosters.com/fr|Safran Aero Boosters]].
  
 ==== Module ==== ==== Module ====
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 ==== Multiphysics ==== ==== Multiphysics ====
  
-Which can manage more than one field of unknown. For example, mechanical unknowns (''x'', ''y'', ''z''), temperature field ''T'', electric and magnetic fields...+Which can manage more than one field of unknown. For example, mechanical unknowns (''x'', ''y'', ''z''), temperature field ''T'', electric and magnetic fields...
 In [[#Metafor]], only mechanical and thermal fields are considered. In [[#Metafor]], only mechanical and thermal fields are considered.
 +
 +
 +----
 +
  
 ===== N ===== ===== N =====
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 ==== Newton-Raphson ==== ==== Newton-Raphson ====
  
-Iterative algorithm which can solve a system of nonlinear equations. In [[#Metafor]], with an implicit integration scheme, Newton's equation is solved at each time step by Newton-Raphson algorithm.+Iterative algorithm which can solve a system of nonlinear equations. In [[#Metafor]], with an implicit time integration scheme, The balance of forces is solved at each time step by Newton-Raphson algorithm. 
 + 
 + 
 + 
 +---- 
  
 ===== O ===== ===== O =====
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 ==== Object-Oriented ==== ==== Object-Oriented ====
  
-Programming method which consists in dividing concepts in classes, to which data and functions to process this data are associated. It is possible to program this way with every language, but it is easier with some. [[#C++]] was used in [[#Metafor]], and [[#Python]] is also object-oriented.+Programming method which consists in dividing concepts in objects. [[#C++]]  and [[#Python]] are both object-oriented languages.
  
-==== Oo_meta ====+==== oo_meta ====
  
-Old name of the [[#C++]] version of [[#Metafor]], when one was certain the conversion from [[#Fortran]] was successful.+Old name of the [[#C++]] version of [[#Metafor]], when the translation from [[#Fortran]] was not yet fully performed.
  
 ==== Oofelie ==== ==== Oofelie ====
  
 Commercial [[#fe|Finite Element]] library used by [[#Metafor]]. OOfelie supplies mathematical operations, management of degrees of freedom and a database. See [[http://www.open-engineering.com/|Open Engineering]]. Commercial [[#fe|Finite Element]] library used by [[#Metafor]]. OOfelie supplies mathematical operations, management of degrees of freedom and a database. See [[http://www.open-engineering.com/|Open Engineering]].
 +
 +
 +
 +----
 +
  
 ===== P ===== ===== P =====
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 Interpreted [[#object-oriented]] programming language. Python is used as an [[#interpreter]] (command line) by [[#Metafor]]. Interpreted [[#object-oriented]] programming language. Python is used as an [[#interpreter]] (command line) by [[#Metafor]].
 +
 +
 +
 +----
 +
  
 ===== R ===== ===== R =====
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 La réponse de Luc à beaucoup de questions, RFTM, ou Read The Fucking Manual. Ironiquement, il n'y a souvent pas de Fucking Manual à lire, ou alors il n'est plus à jour, mais bon, faut pas chercher... La réponse de Luc à beaucoup de questions, RFTM, ou Read The Fucking Manual. Ironiquement, il n'y a souvent pas de Fucking Manual à lire, ou alors il n'est plus à jour, mais bon, faut pas chercher...
 +
 +
 +----
 +
  
 ===== S ===== ===== S =====
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 Software initally created by the LTAS, in the University of Liège. Samtech, first spin-off of the university, has commercialized Samcef for years. In the laboratory, Samcef is used through [[#Bacon]] to import complex geometry in [[#Metafor]]. Software initally created by the LTAS, in the University of Liège. Samtech, first spin-off of the university, has commercialized Samcef for years. In the laboratory, Samcef is used through [[#Bacon]] to import complex geometry in [[#Metafor]].
 +
 +
 +----
 +
 +
  
 ===== T ===== ===== T =====
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 In [[#Python]], a tuple corresponds to a ordered set of values which cannot be modified. For instance, ''(1, 2, 'a', "tuple")'' is a tuple. A tuple can include another tuple. In [[#Python]], a tuple corresponds to a ordered set of values which cannot be modified. For instance, ''(1, 2, 'a', "tuple")'' is a tuple. A tuple can include another tuple.
 +
 +
 +
 +----
 +
  
 ===== V ===== ===== V =====
  
 ==== VCS  ==== ==== VCS  ====
-Version Control System. Software in charge of the management of changes in [[#Metafor]] source code, and the verification of the [[#battery]]. VCS allows the simultaneous modification of the code by several developers, and facilitate updates and synchronization. Thanks to VCS and to a lot of work, only one version of [[#Metafor]] exists today.+ 
 +Version Control System. Software in charge of the management of changes in [[#Metafor]] source code, and the verification of the [[#battery]]. Two VCS are used today for Metafor: [[https://subversion.apache.org/|Subversion]] and [[https://git-scm.com/|git]]. 
 +these VCS allow the simultaneous modification of the source code by several developers, and facilitate updates and synchronization. Thanks to the VCS and to a lot of work, only one version of [[#Metafor]] exists today.
  
 ==== Volume Element ==== ==== Volume Element ====
  
-[[#FE|Finite Element]] which has a volume geometry in 3D (such as an hexaedron), and a surface geometry in 2D (such as a quadrangle). Volume elements are are a subset of elements, such as contact elements, pressure elements, shells, ...+[[#FE|Finite Element]] which has a volume geometry in 3D (such as an hexaedron or a tetrahedron), and a surface geometry in 2D (such as a quadrangle or a triangle). Volume elements are a subset of "elements". Other types of elements include contact elements, pressure elements, shells, ...
  
-==== Vtk ====+==== VTK ==== 
 + 
 +Graphical library for displaying 2D/3D meshes and results in the graphical user interface of Metafor. 
 + 
 + 
 +----
  
-Graphical library used by [[#Metafor]], under LGPL license. 
  
 ===== Z ===== ===== Z =====
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 ==== Z-Mesh ==== ==== Z-Mesh ====
  
-Home made preprocessor, initially created by Laurent Stainer. Z stands for Zorglub (what else could it be ?)Since the 23/03/06, it is no longer used, since the import from [[#Bacon]] is directly done with [[#Python]].+In-house preprocessor, initially created by [[https://scholar.google.fr/citations?user=xvxfKIoAAAAJ&hl=fr|Laurent Stainer]]"Zstands for [[wp>Zorglub]]It has been used as a preprocessor for Metafor until 23/03/2006. 
 + 
 + 
 + 
 + 
 + 
 + 
doc/user/general/glossaire.1508919933.txt.gz · Last modified: 2017/10/25 10:25 by boman

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