Code_Aster
®
Version
7.4
Titrate:
Introduction to Code_Aster
Date:
22/07/05
Author (S):
Mr. ABBAS, F. WAECKEL
Key
:
U1.02.00-C
Page
:
1/14
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HT-66/05/004/A
Organization (S):
EDF-R & D/AMA
Instruction manual
U1.0- booklet: Introduction to Code_Aster
Document: U1.02.00
Introduction to Code_Aster
Warning:
One proposes to describe here, the philosophy and the applicability of Code_Aster, without developing in
detail methodologies of study usable.
This document is a first making of contact with Code_Aster and was thus written with a concern of
concision. It does not have the role to index all modelings or possible types of analysis with
Code_Aster, and is not substituted to in no case with the plate of the Version 7 which draws up a panorama of it
exhaustive.
All the information, provided here or in the various manuals, is given to describe, with
maximum of precision, contents of Code_Aster. They do not have as an ambition to deliver a formation with
numerical modeling of the behavior of the mechanical structures. Code_Aster is only the establishment of
methods described and shown in various works to which the reader will have to refer, in complement
reference material, if necessary. The manuals of Code_Aster suppose acquired in addition
a formation with the mechanics of the solids and the finite element method.
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Introduction to Code_Aster
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Count
matters
Code_Aster
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Introduction to Code_Aster
Date:
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1
The study of the mechanical behavior of the structures
1.1
A general code
Code_Aster is a general code for the study of the mechanical behavior of the structures.
The priority applicability is that of the mechanics of the deformable solids: that justifies it
a number of functionalities attached to the mechanical phenomenon. However, the study of the behavior
mechanics of the industrial components requires beforehand the modeling of the stresses
which they are subjected, or of the physical phenomena which modify the parameters of it
behavior (fluid intern or external, temperature, metallurgical phase shift, efforts
of electromagnetic origin…). For these reasons, Code_Aster offers several possibilities of
“chaining” of the mechanical phenomenon with the phenomena thermics or accoustics, or with
external software, as well as a “kit” of construction of coupled hydro-mechanical thermo problems.
Although Code_Aster can be used for many problems of structural analysis (code
General), it was developed in particular to allow the study of the components of hardware or of
machines used in the field of the electricity production and transmission. Thus the priority was
data with the modeling of the isotropic metal structures, géomatériaux and the components
of composite material or reinforced concrete structure.
The nonlinear analyzes, as well in mechanics in thermics, are in the middle of Code_Aster:
their effective processing required the adjustment of powerful and relatively simple algorithms
of use, even if the goal is not to make them function in “block box”. For the studies
complexes, it is thus necessary to include/understand the nature of the operations carried out by the code, so
of being able to control them in an optimal way: one refers then to the theoretical notes giving the details
the modelings and methods, gathered in the Manual of Reference.
The setting under Quality assurance to be able to carry out industrial studies justifies several
choice:
·
existence of a version of fixed and documented reference code,
·
provision of complete, fixed but parameterized algorithms,
·
principle of orthogonality of the controls (independence of the context of use),
·
objective of complétude of modelings usable.
1.2
Method for calculation with Code_Aster
A structural analysis carried out with Code_Aster consists of the sequence of a certain number of
controls described within a “command file” in format text. The engine and the interpreter
this command file is the language script PYTHON. It is thus possible to use all them
functionalities brought by PYTHON. See in particular the docs [U1.03.01], [U1.03.02] and them
examples of use [U1.05.00] and [U1.05.01]. Each control (for example reading of the mesh,
affection of the data material, linear static calculation) produced a “concept result”, together of
structures of data which the user can handle and re-use in the further orders of
calculation (for example mesh, the field of data material, the field of displacements…).
The syntax of all the controls is described and commented on in the manuals U4 and U7 of
documentation of Use.
In order to simplify the task of the user, there are total controls which gather
the sequence ad' hoc of operations for a certain number of calculation case (for example static
linear - control MECA_STATIQUE, nonlinear statics - control STAT_NON_LINE, thermics
nonlinear - control THER_NON_LINE, etc). Some were developed directly of
integrated manner, others are macros-controls in Python which do nothing but manage the calls
with the various unit controls (as MACRO_MATR_ASSE which makes it possible to calculate and
to assemble the matrices of mass, damping and rigidity of a structure).
There are also macro-controls especially dedicated to certain applications (see [§4]).
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Introduction to Code_Aster
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At the end of a calculation, it is often possible to enrich the data-processing object containing the “concept
result “obtained, by carrying out other calculations a posteriori: for example, starting from the field of
displacements and of the stresses at the points of Gauss obtained in a mechanical calculation, one can
to calculate the field of deformations, the stress field interpolated to the nodes, etc One then invites
that to implement a “option” of calculation, which is affublée of a barbarian name, but which follows one
logic “quoi_où_comment” (for example option EPSI_NOEU_DEPL for the deformations
data with the nodes starting from the values of displacements).
1.3
Phenomena, modelings, finite elements and behaviors
1.3.1 Concepts
One calls “phenomenon” a family of physical problems resting on the same type
unknown factors (and associated a type of conservation equation): for example, the phenomenon
mechanics calls upon the unknown factors of displacement, the thermal phenomenon with the unknown factors of
temperature. According to modeling used, the number of unknown factors of this type can vary (for example
one needs in each node only for one unknown factor for temperature in 3D, but 3 unknown factors are used
for the hulls).
Note:
For the thermo problems hydro-mechanical one coupled, this concept was extended in
measure where one gathers, in this case, under the “mechanical” phenomenon, the whole of
conservation equations associated with the hydro-mechanical thermo problem.
One calls modeling the manner according to which continuous equations governing a phenomenon
given are discretized, with the aid of possible complementary assumptions (plane deformations,
model of beam, models hull…). In mechanics, for example, one can find modelings
3D, 2D plane deformations, 2D forced plane, hulls 3D, plates, beams of Euler, beams of
Timoshenko, pipes, etc… Each modeling uses a set of degrees of freedom which are to him
clean: for example displacements in the 3 directions of space for modelings of
continuous medium 3D, 3 displacements and 3 rotations for hulls 3D, etc
The couple phenomenon/modeling makes it possible to affect in a bijective way a type of finite element to
each type of mesh of the mesh.
In Code_Aster, one calls “finite element”, for a given modeling, the triplet consisted:
·
the nature of the mesh support (representing a piece of volume or border: hexahedron,
tetrahedron, triangle, quadrangle, segment…) : it is topological information (it includes it
a number of nodes);
·
laws of interpolation of the unknown factors (functions of form);
·
“options” of calculation which the element “can” calculate (the operations for which
calculation of the adequate integrals was programmed: for example, elementary term of
rigidity, elementary term of surface force, elementary term of mass…).
A characteristic of Code_Aster is to affect the boundary conditions and the loadings of edges to
specific elements of edge, and not with the borders of the finite elements of volume.
The behavior is at the base a physical notion related to the properties of material. It is expressed
then in a mathematical way. For example, in mechanics, one calls relation of behavior
the relation which binds the stress field to the field of deformations, is in a direct way
(elastic behavior), that is to say in an incremental way (incremental behavior). During one
calculation, the relation of behavior is expressed in each point of Gauss. In thermics, one used
the term “behavior” to qualify the physical field associated with the resolution of the equation
model of conduction-dissemination: two great classes of behaviors, which comprise
each one several subcategories, are it thermal (possibly coupled with the hydration) and it
drying.
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1.3.2 The mechanical phenomenon
The mechanical phenomenon is modelized to achieve two main goals:
·
determination of the internal state, in particular of the state of stress in any point of one
structure, under various stresses representing the conditions of operating.
knowledge of this state of stress makes it possible to continue the analysis of the behavior
mechanics from the point of view:
- rules of construction particular to each type of structure, in particular them
Rules of Design or Construction (RCC…) ;
- harmfulness of defects and their possible propagation: defects inherent in
development process of the component or the structure (inclusions, imperfections
geometrical…) or resulting from the conditions of operating (cracking, erosion…) ;
-
study of the behavior in cyclic loading and analysis with fatigue;
-
prediction of the safe loads with evolution of the internal state.
·
determination of the deformed configuration induced by a permanent loading (static)
or resulting from a slow evolution (quasi-static) or more rapid (dynamic) of
loadings or of the boundary conditions. The knowledge of this deformed configuration,
and possibly speeds and of corresponding accelerations, allows to continue
analysis of the mechanical behavior from the point of view:
-
vibratory and acoustic behavior;
-
transmission of the stresses to other structures or components;
- risks of impact with the close structures to determine the faults of
operation or the parameters of wear which can result from it.
The levels of modeling which intervene for the study of this phenomenon are:
·
the representation of the structure starting from the geometrical form, with several modes of
representation possible being able to coexist:
- continuous medium corresponding to a three-dimensional, or two-dimensional geometry
with various assumptions (forced plane, plane deformations, axisymetry
complete or adapted to the decomposition of the loadings in modes of FOURIER),
- structural elements corresponding to a medium with average layer, a medium with fiber
average or a discretized medium.
·
the representation of the behavior of materials, possibly different, in any point
of a structure, with relations of behavior allowing to represent different
conditions of use. Many relations of behavior are available
(cf plate): linear and nonlinear elasticity, nonlinear hyperelasticity, viscoelasticity,
elastoplasticity, élasto-visco-plasticity, damage. Coefficients of the relations of
behavior can in general depend on variables known as “of piloting” such as
temperature, the metallurgical state, the degree of hydration or drying of the concrete, fluence,
etc
·
the representation of the boundary conditions and the loadings, for which one has
functionalities allowing to represent in any point of the structure, total reference mark or in
reference mark defined by the user:
- conditions of DIRICHLET: imposed displacement or linear relations enters
components of displacement,
-
conditions of NEUMANN: force imposed specific or surface loadings and
linear, in particular allowing to represent the loadings of pressure,
-
voluminal loadings, in particular allowing to represent gravity and them
centrifugal loads of the bodies in rotation.
These boundary conditions and loadings can depend on time (or of the frequency)
and of one or more variables of space.
Nonthe linearities taken into account in the mechanical phenomenon are nonthe linearities of
behavior, and nonlinearities geometrical (great displacements and great rotations, large
deformations, contact and friction, buckling).
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1.3.3 Associated phenomena
To supplement the representation of the environment of exploitation of the mechanical components, it
choice was made include in Code_Aster of the functionalities allowing the modeling of
phenomena frequently associated the mechanical phenomenon.
1.3.3.1 Phenomenon
thermics
It makes it possible to determine the thermal response of solid media in steady state (problem
stationary) or transient (evolutionary problem). One modelizes solid conduction, the convectif exchange,
the heat transfer between walls, and the radiation ad infinitum. The thermal phenomenon can include
modeling with the heating or the cooling of the metallurgical phase shift of steels,
what makes it possible to simulate the operations of heat treatment or welding (the identification of
behavior is based on experimental diagrams TRC).
By analogy solved equations, the thermal phenomenon can also be used for
to modelize the hydration (the unknown factor is the degree of hydration) or the drying of the concrete (the unknown factor is
water concentration).
1.3.3.2 Acoustic phenomenon
The acoustic phenomenon is modelized to achieve two main goals:
·
the study of the acoustic propagation in closed medium corresponding to the equation of HELMHOLTZ
in a compressible fluid, for fields of propagation to complex topology.
knowledge of the field of pressure makes it possible to continue the acoustic analysis for
to determine:
-
the field of acoustic levels (expressed in dB),
-
fields of active and reactive acoustic intensity.
·
the study of the vibroacoustic coupled problems 3D corresponding to the behavior
vibratory of a structure in a limited field of compressible, nonviscous fluid.
1.3.4 “Couplings” of phenomena
So that there is no ambiguity, one will distinguish:
·
the chaining of two phenomena: feasibility study of the first phenomenon which one uses them
results like data of the second,
·
coupling of two phenomena: simultaneous resolution of the two phenomena with
actually coupled equations (cf [§1.3.4.2]).
1.3.4.1 The chainings intern in Code_Aster
The chaining can be carried out inside Code_Aster or between the aforementioned and an external software
(cf [§5.2]).
The chainings currently carried out within Code_Aster are as follows:
·
thermics - mechanics: all the mechanical characteristics of materials can
to depend on the temperature and the algorithms available for the mechanical phenomenon
allow to exploit the results of a preliminary thermal calculation
(deformations
anelastic
: thermal dilations, shrinking of the concrete…) carried out on a mesh
possibly different,
·
thermics - metallurgy: after a thermal calculation, it consists in calculating the proportions of
various metallurgical phases of steels,
·
thermics - metallurgy - mechanics: taking into account of four mechanical effects of
metallurgical transformations (deformation of phase shift, amendment of
mechanical characteristics, plasticity of transformation, restoration of work hardening of origin
metallurgical),
·
electric - mechanics: integrated into the mechanical phenomenon, the electric coupling is limited to
the taking into account of the forces of LAPLACE induced by currents of short-circuit in
electric cables,
·
fluid-mechanics: assignment of field of pressure on a wall deduced from a calculation from
mechanics of the fluids.
Code_Aster
®
Version
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Introduction to Code_Aster
Date:
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1.3.4.2 Truths couplings
Porous environments
The or not saturated saturated porous environments (géomatériaux, grounds, concrete) must be studied in
coupling the three equations of mechanics, thermics and hydraulics. The user chooses
the behaviors which it wishes to use among a kit of thermo models hydro-mechanical known as
“THM”. It can thus choose to take into account or not the effect of the temperature, and to represent
one or two pressures. The choice of each behavior associated with the phenomena selected
is carried out within this framework also.
Interaction fluid-structure
Three types of couplings are available in the field of the interaction fluid-structure:
·
the calculation of clean modes of a structure containing (or bathing in) a fluid at rest
(with or without free face),
·
the calculation of the vibrations of a structure in a flow and the estimate of
the damage while resulting by vibratory fatigue or wear,
·
the taking into account of a boundary condition of infinite fluid the field type.
1.4
Several methods of analysis
1.4.1 Quasi-static/Transitory statics/
To implement various modelings, one has several methods of analysis which
correspond to various processes of application of the stresses.
Analyze static: it corresponds to permanent stresses for the processing of thermics
stationary and the thermomechanical one. For the linear analyzes, the results obtained can be
compounds linearly, according to the needs, and are usable to describe the initial state of a process
evolutionary.
Quasi-static analysis: for all the mechanical processes where one can neglect the phenomena
of inertia, implicit incrémentaux algorithms are available to solve the equations of
behavior nonlinear with taking into account of loadings and boundary conditions evolutionary.
Analyze transitory: in linear and nonlinear thermics, with possible taking into account of the effects
metallurgical for metals and of the hydration and drying for the concretes, like for
the thermo problems hydro-mechanical one by neglecting the effects of inertia on the mechanical part.
1.4.2 Dynamics: physical or basic concept basic modal
For the processes where the effects of inertia and propagation must be taken into account
(vibratory mechanics, accoustics), one speaks about dynamic analysis.
The analysis in physical base is the resolution of the equations in the conventional base of the degrees of
freedom physics.
The analysis in modal base rests on the preliminary calculation of the values and clean vectors of
structure, and consists in projecting the equations to be solved on a basis of clean vectors: the number
degrees of freedom of the system to be solved is proportional to the size of the modal base used. It
is necessary that the selected modal base is of sufficient size to reproduce the main ones
physical phenomena: modal basic quality standards exist and can be checked
(cf [§3.4.3]).
For these two types of analyzes in physical or modal base, the calculation of answer can be carried out
into temporal or harmonic (in the linear case).
For the seismic analysis, one can also formulate the problem moving imposed in one
relative reference frame (without the movement of drive).
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The linear dynamic analyzes can be made by including the effects, of the second command on
rigidity, of the initial static stresses calculated as a preliminary (geometrical rigidity, stiffening
centrifugal).
For the nonlinear problems, two methods of analysis are available:
·
analysis by modal recombination with boundary conditions nonlinear localized
for problems with shock,
·
nonlinear dynamic analysis in physical base.
1.4.3 Decomposition in modes of Fourier
The analysis in mode of Fourier is intended to calculate the linear response of a structure for geometry
axisymmetric subjected to nonaxisymmetric loadings by netting only one section of
structure.
Concretely, the loading being broken up into Fourier series, the resolution is made for each
mode of Fourier then the total answer is obtained by recombination of the results on each
mode.
1.4.4 Under-structuring
Under structuring consists in gathering several finite elements within a macronutrient and with
“to condense” the whole of their rigidity on the degrees of freedom (fewer) of it
macronutrient.
The resolution of the total problem is limited then to the determination of the unknown factors carried by
macronutrients then with the calculation of the unknown factors carried by each “small” element in manner
independent within each macronutrient.
The advantages of this method are the savings of time and memory, when the complete structure
is made of reproduced elements several times by translation or rotation.
In dynamics: the modal analysis and calculation of the harmonic or transitory answer can be
carried out in conventional dynamic under-structuring by the methods of Craig-Bampton, Mac Neal
or for the method known as of the modes of interface.
For the structures having a cyclic repetitivity, the methods available allow
to calculate the clean modes of the total structure starting from the dynamic behavior of a sector
basic.
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2
A method of resolution: finite elements
For the resolution of the various mentioned problems, the only method of established discretization
currently is the finite element method.
2.1
A parameterized establishment of the finite element method
A particular effort was made to parameterize the establishment of the finite element method.
options of calculation necessary to each method of analysis (static, quasi-static, dynamic) and for
each phenomenon (mechanical, thermal, acoustic) are treated overall for all
structure, whatever the modelings retained for a particular study.
Among the possibilities offered by this architecture, let us quote:
·
independence enters the topology of discretization (“
mesh
”) and properties
of interpolation of the finite elements assigned to these meshs (“model”) from where the diversity of
modelings usable on the same mesh,
·
the diversity of the relations of behavior and the properties of materials usable in
the same model,
·
processing of the boundary conditions and the loadings by specific finite elements
of edge, to allow their localization without ambiguity, in particular for the mediums
continuous,
·
a systematic procedure allowing to treat the dependence of the material properties
and of the boundary conditions with various parameters (temperature, time, variable
of space…),
·
structures of data allowing to use all modelings with the different ones
algorithms of resolution.
Concerning the processing of the boundary conditions, let us announce that the method currently privileged
is that of the dualisation. It makes it possible to represent any system of linear relations between
discretized unknown factors, in particular for the connection of different modelings or the catch in
consideration of additional local assumptions (flatness of a face of continuous medium…). One
another method by elimination of the imposed degrees of freedom, exists in complement for calculations
linear.
Concerning the methods of classification of the unknown factors, of storage of the assembled matrices and
resolution of the linear systems on which the various algorithms rest, one has
today of two direct methods, and an iterative method:
·
multi-frontal method,
·
factorization LDL
T
,
·
packaged combined gradient (iterative method).
One can add solvor FETI for decomposition of fields of which a first version (limited to
linear and with certain types of boundary conditions) is present in version 7.4.
These methods are associated algorithms of renumerotation of the degrees of freedom allowing
to optimize the size memory necessary to store the matrices.
2.2
A wide library of finite elements
The library of finite elements is parameterized to allow the assignment, with the various meshs
recognized, of the discretized formulations of the phenomena available.
2.2.1 Continuous mediums
One calls continuous medium a portion of three-dimensional or two-dimensional structure, treated
like a volume.
Modelings 3D are the simplest forms of continuous medium, because they do not call upon
no additional assumption. In modelings 2D, one removes an equation, but one
must add assumptions: for example of plane strains or plane stresses in
mechanics, of axisymetry in thermics and mechanics.
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There are also elements taking of account discontinuities (eg: fissure) by the method
level-sets (elements XFEM).
2.2.2 Components of structure
The structural elements are built by integrating assumptions on the behavior
kinematics three-dimensional (representing more or less well the phenomena of bending, torsion,
shearing, roll…). One can classify them in three categories:
·
elements with average layer (plates, hulls): each type of element rests on
assumptions of variation of the unknown factors in the thickness, which makes it possible to calculate the value in
any point from that taken on the average layer (and possibly the faces lower and
higher in thermics),
·
elements with average fiber (bars, beams, pipes, cables): the assumptions connect for
each transverse section the value of the unknown factors in any point with that taken on fiber
average,
·
discrete elements (masses, springs, shock absorbers…) : they make it possible to introduce on
specific meshs or of the segments of the characteristics expressed in a reference mark
Cartesian unspecified.
2.2.3 Connections of modelings
The establishment retained for the Finite element method makes it possible to treat structures
modelized with various types of machine elements (continuous mediums or structural elements).
The connection of finite elements being based on different degrees of freedom, in the same node, can
to be made by writing linear relations adapted to the nature of the connection. A methodology
particular was developed to transmit as correctly as possible (within the meaning of
least squares) torques of effort. One can thus represent the connection satisfactorily
between a medium 3D and beams, plates, hulls or pipes, as well as the connections
hull-beam, hull-pipe or beam-pipe.
The method HARLEQUIN also makes it possible to make connections between mesh and/or phenomena
different.
2.3
Heterogeneous modelings
Techniques of homogenization make it possible to represent at lower cost a network of tubes
bathing in an incompressible fluid, multi-layer composite hulls, or beams
multifibre.
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3
Tools of study
3.1
Complements and operations on the mesh
The concept of mesh used by Code_Aster is tiny room to its simpler expression: list nodes
and their co-ordinates, lists meshs and of their topology. With these entities the notion is added of
groups of nodes and group of meshs. These groups make it possible to affect different
characteristics of modeling (finite elements, materials, boundary conditions, loadings…) and
to lead the examination of the results (selective extraction of components). This party taken allows
to build a mesh, either by manual drafting without useless heavinesses, or by interfacing with
mailleurs commercial (Gibi, I-DEAS, GID) or free (GMSH).
The user can create groups of nodes or meshs constantly in the unfolding of
calculation, thanks to logical or geometrical criteria. One can also modify the structure of
data containing the mesh: change of reference mark, addition of additional nodes on
meshs, creation of new meshs or groups of meshs, destruction of meshs, etc the addition and
the ablation of matter can thus be modelized simply.
3.2
Catalog data material
A catalog of data material under AQ gives access to the values of the parameters of laws of
behavior for various materials usually used in the studies. Characteristics
materials can be directly included in the command file thanks to an operator
specific. For the free version, all the equipment of the catalog is available but the base is empty (with
the load of the user to fill it with his data).
3.3
Processing and analysis of the results
3.3.1 Operations on the fields
The computed fields can be used in all kinds of algebraic combinations. In
analyze linear, one can thus for example deduce the response to a loading complexes
answers to the unit loadings on which it break up.
3.3.2 Recording of values
Operations of extraction of the fields of results are available on nodes or meshs. It
is also possible to define a path of unspecified observation independent of the initial mesh.
Various calculations are proposed on the extracted fields (average, standard deviations, invariants tensorial,
passage in local axes, etc). For the temporal or frequential evolutions, it is possible
to extract the deformation at one moment (a frequency) or the answer from a particular size.
3.3.3 Impression of the results
The results can be printed in an easily consultable form or with the format of the tools of
visualization (Gibi, I-DEAS, GMSH or ENSIGHT). The user can integrate into the impressions of
results of the personalized titles integral of the information extracted the context automatically from
the study. Several tools are available to limit the impression to portions of the computed fields.
One can also plot curves with various formats (postscript or other formats of images) with
the aid of the tracer xmgrace.
3.4
Quality control of the results
Many functionalities make it possible to control the quality of the results of a study or of in
to facilitate its implementation.
Code_Aster
®
Version
7.4
Titrate:
Introduction to Code_Aster
Date:
22/07/05
Author (S):
Mr. ABBAS, F. WAECKEL
Key
:
U1.02.00-C
Page
:
12/14
Instruction manual
U1.0- booklet: Introduction to Code_Aster
HT-66/05/004/A
Estimators of error and adaptive mesh
Two categories of estimator of error are available. Coupled with the software of refinement/
déraffinement LOBSTER (chaining interns in Code_Aster via macros-control),
they make it possible to adapt the mesh in the course of calculation in order to reach a given precision, for one
cost optimal calculation.
Checking of the quality of a modal base
Criteria of checking of the quality of a modal base make it possible to make sure that the number of
clean modes selected makes it possible to correctly represent the phenomena which one wishes
to study.
Use of incompatible mesh
Operators of projection allow to continue on a second mesh a calculation carried out on
a first mesh. One can thus use different mesh in thermics and mechanics (in
including for example a block fissures in the structure only at the time of its analysis in
exploitation, after having calculated on a simpler mesh the residual stresses due to sound
manufacturing process).
Automatic Recutting of the pitch of time and piloting of the loading
In the event of nonconvergence of the total algorithm of resolution, the user can ask so that
the code engages of him even a recutting of the pitches of time in order to allow convergence.
In addition, it is also possible, in order to facilitate the convergence of calculations, to control the application
progressive of the loading by the value of a degree of freedom or a deformation.
Indicators of discharge and loss of radiality
These indicators make it possible a posteriori to check the validity of the assumptions formulated on
nonlinear behavior of a structure, and relevance of the mode of application of the loading
retained (not of load).
Code_Aster
®
Version
7.4
Titrate:
Introduction to Code_Aster
Date:
22/07/05
Author (S):
Mr. ABBAS, F. WAECKEL
Key
:
U1.02.00-C
Page
:
13/14
Instruction manual
U1.0- booklet: Introduction to Code_Aster
HT-66/05/004/A
4 Them
tool-dedicated
4.1
Definition and procedure
One calls tool-dedicated of the tools very related to the trade of operator of hardware of production and
electric distribution, and using Code_Aster as solvor. Tool-dedicated can have one
more or less strong integration with Code_Aster. One distinguishes two cases from figure:
·
integration with the command file Aster as a macro-control (including creation
mesh starting from simple geometrical data),
·
production by a separate tool (pre-post autonomous processor) of command files
controlling calculation Aster, and processing in this tool of the files of the recovered results.
4.2
Thededicated available ones
Thededicated following ones are available in the form of macro-controls of Code_Aster:
·
ASCOUF
: analyze with the rupture of fissured elbows or with under-thicknesses,
·
ASPIC
: analyze nonlinear healthy or fissured prickings,
·
CABRI
: calculation of flanges,
·
CALC_PRECONT
: setting in voltage of cables of prestressing.
Thededicated following ones communicate with Code_Aster by command files and of
results:
·
MEKELEC
: analyze switchyards and air lines,
·
EVEREST
: dimensioning of the metal frames and the pylons in
lattice,
·
GEVIBUS
: flow induced vibrations of the tubes of steam generators,
·
EPICURE/SECURE: harmfulness of defects in a tank.
Code_Aster
®
Version
7.4
Titrate:
Introduction to Code_Aster
Date:
22/07/05
Author (S):
Mr. ABBAS, F. WAECKEL
Key
:
U1.02.00-C
Page
:
14/14
Instruction manual
U1.0- booklet: Introduction to Code_Aster
HT-66/05/004/A
5
Exchanges with other software
5.1
Modes of exchanges
Code_Aster can receive in data of the files coming from calculations carried out beforehand by
external software. It can also export its results under an exploitable format by others
tools. For certain types of analyzes (for example interaction ground-structure or ground-fluid-structure with
the software MISS 3D) the two types of chaining can be activated.
The exchanges with other software are currently done either with format I-DEAS, or in a format
specific to the chained software. Several controls of Code_Aster allow the reading or the writing
objects to be transmitted (fields of results, matrices, loadings…). In certain cases
(MISS 3D), of the macro-controls facilitate the implementation of a chained calculation. Lastly, it
development of format MED creates a standard for the exchange of the files which is brought to
to develop.
5.2
Software interfaced with Code_Aster
The software of mesh interfaced with Code_Aster is Gibi (sub-assembly of CASTEM2000),
I-DEAS or GMSH. For the visualization of the results, one can use Gibi, I-DEAS, ENSIGHT or
GMSH.
The main computation softwares which can be chained with Version 7 of Code_Aster are them
following:
·
CIRCUS
: vibrations of the circuits of pipings and lawful calculation,
·
N3S-SYRTHES: analyze thermal in the presence of flow,
·
EOLE
: acoustic propagation in flow,
·
Dynamic EURO_PLEXUS
rapid
·
MISS 3D
: propagation of waves in the grounds laminated (seism) by elements of
border,
·
LADY
: analyze vibratory experimental,
·
LOBSTER
: refinement and déraffinement of mesh starting from an estimator
of error,
·
MEFISTO
: calculation of reliability,
·
SATURN
: code of mechanics of the fluids.