Functionalities

Code_Aster provides, well beyond the standard function of any other thermo-mechanic calculation code, a whole array of analysis methods and multi-physic models. Its application domain extends from seismic analysis, to porous medium, without forgetting acoustics, fatigue, stochastic dynamics… Its models, its algorithms and its solvers have improved in robustness and thoroughness (1000000 lines of code, 200 operators). Completely open, it is chained, coupled and encapsulated in thousands of ways. All in all, the user has complete freedom of choice.

Phenomena

Mechanics

• Static, quasi static linear or not
• Dynamic, linear or not, on a physical or modal base
• Failure, damage and fatigue
• Ground-Structure, fluid-structure and ground-fluid-structure interaction

Thermo-Hydro-Mechanics

• Stationary, transitory, linear or not
• Fixe or mobile coordinate system

Associated phenomena

• Acoustic
• Metallurgic
• Hydration and drying

Analysis types

Standard

Fourier mode decomposition

Sub-structuring

Model superposition

Adaptive meshing

Sensitivity calculation

Resetting and optimization

Multiphysic

Internal chaining with thermal problems

• Hydration, drying
• Metallurgy

Internal Chaining with mechanics

• Thermal problems
• Metallurgy
• Hydration and drying
• Electricity

Internal coupling

• Thermo-hydro-mechanics
• Fluid-structure

External coupling with other codes

• Ground-(fluid)-structure (MISS3D)

External chaining with other codes

• Pipework: CIRCUS
• Hydraulic: Code_Saturne
• Thermal problem: SYRTHES
• Electromagnetism: Flux2D/3D
• Rapid Dynamics: EUROPLEXUS
• Experimental vibration analysis: LADY

Loading

Mechanic

• Efforts at nodes or divided efforts
• Pressures
• Objects subjected to their own weight
• Centrifugal acceleration
• Imposed movement
• Anelastic strain
• Effects of wind

Thermal Problems

• Temperature
• Linear or non-linear flow
• Forced convection
• Non confined radiancy
• Heat exchanges between boundaries
• Heating due to Joule effect

Specific loads (following forces, electromagnetic, initial states)

Static and dynamic non linearities

Geometric

• Geometric re-actualisation, large strains, large rotations
• Following forces
• Piloting with displacements, arc lengths, strain, or criteria crossing
• Discharge indicators and non-radiality of load
• Contact and friction
• First-order buckling

Materials (80 behaviour laws: Chaboche, Lemaitre, Mazars, Cam-Clay, Rousselier…)

• Non-linear elasticity, hyper-elasticity, visco-elasticity, elasto-visco-plasticity
• Local and with gradient: elasto-plasticity
• Local and with gradient: damage
• Elsato-Visco-plasticity
• Metallurgic effects
• Material data which varies with temperature, metallurgic state, hydration, drying and creep
• Progressive strain
• Hydration, retracting and creep of concrete
• Geo-materials

Dynamics

Modal analysis

• With or without dampening (viscous, hysteric, modal)
• Direct or via sub-structuring
• Normalising, filtering, and modal parameters

Transitory linear response

• Direct
• On a modal base
• By sub-structuring

Transitory response with local non-linearities (on a modal base)

• Shocks (modal base verification criteria, buckling)
• Friction
• Fluid lamina

Harmonic response

• Direct
• On a modal base
• By sub-structuring

Random response

• Parametric and non parametric probabilistic response (random models)
• Stochastic (random loading)

Direct non linear analysis

• Shocks
• plasticity, damages
• Contact and friction

Sub-structuring

• Classic or cyclic
• Modal, transitory or harmonic analysis

Seismic analysis

• With shocks or multi-support
• Spectral, direct linear transitory or on modal base
• Modal dampening calculations (RCC-G)

Experimental measurements extrapolation

• Temporal or frequential

Interactions

Fluid-Structure

• Structure-incompressible flow interactions; turbulent stress
• Vibro-acoustics (free surface)

Ground-structure and ground-fluid-structure

• Absorbent frontier element
• Frequential coupling with MISS3D

Thermal Analysis

Linear and non linear thermal problems

• Phase changes
• Hydration and drying
• Mobile coordinate system resolution

• Radiance in open space

Metallurgic evolutions

• Steels, Zircaloy
• Phase hardness calculations

Thermal treatments and welding

Geo-technical civil engineering

Concrete behaviour laws (reinforced or pre-constrained), geo-materials

Hydration, drying, creep occurring in different time lapses

Effects of passive armatures or of pre-constraints with elasto-plastic behaviours

Creeping-cracking coupling

Thermo-hydro-mechanics (porous medium, effective constraints formulation, behaviour laws kits…)

Specific loadings (hydric or gaseous flux)

Excavation procedure

Failure, damages, fatigue and decay of structures

Global energy restitution rate

• Thermo-elasticity: G
• Thermo-elasto-plasticity: GP and GTP

Sensitivity of G to 2D domain variations

3D Local energy restitution rate

Constraint intensity factors

Fragile and ductile failure models, instigation and instability

Specific load piloting

Local or non local damage

Crack opening (joint elements)

Increased damage

Fatigue analysis

• Load history
• Counting methods for multi-axial or mono-axial loads; either deterministic, random or periodic
• Specific criteria application

RCC-M criteria verification

Cyclic load Zarka-Casier method

Progressive wear

Boundary analysis

Micro-macro approach: poly-cristallin models

Quality of studies

Spatial error indicator

• Mechanic (in pure residue, by smoothing)
• Thermal (in pure residue)

Refining/coarsening of the mesh with HOMARD (either piloted by an indicator or uniform)

More robust finite elements

• Mechanic (sub-integrated, incompressible)
• Thermal (lumped model)

Diagnostic of the mesh and mesh geometry

Division of the mechanical time interval with reference to the thermal time interval

Sensitivity Calculations

• Mechanic (linear statics, harmonic dynamics)
• Thermal (linear and non linear)
• With respect to materials, to loads and to domain variations

Resetting of parameters

• Material or load
• With respect to a test case or to numerical results

Modelling

Material data catalogue

Incompatible mesh linking, model superposition

Model linking (shell-3D, beam-pipe)

Plane stress condition which can be adapted to any model

Beam characteristics calculation

Homogenisation (composites, repeating… )

Adding or removing material

Element Library (360 finite elements)

Mechanic

• 2D (C_PLAN, D_PPLAN), 2D axi (with or without Fourier decomposition), 3D, sub-integrated, incompressible
• Bars, beams (simple or multi-fibre), pipes, plaques, shells, membranes, cables, discrete or non-deformable elements

Thermal

• 2D, 2D axi (with or without Fourier decomposition)
• 3D
• Shells

Hydration–Drying: 2D, 2D axi, 3D

THM coupling: 2D, 2D axi, 3D

Solvers

Linear (Gauss, LDLT, multi-frontal parallelism, GCPC

Non linear (Newton…)

Integration methods (Runge-Kutta, Newmark…)

Modal Methods (Puissance, Lanczos, IRAM)

Extended parameter setting. Several renumbering, stocking, preconditioning, post verification strategies

Boundary conditions by elimination or by dualisation via Lagrange

Dedicated Tools

Picking and pipe-work bends: ASPIC/ASCOUF

Dowelled assemblies: GOUJ2ECH

Electric Networks: MEKELEC

Pylons: EVEREST

Steam Generator tubes: GEVIBUS

Software environment

Pre-Post processing: I-DEASTM, GIBI, GMSH, ENSIGHT, AGRAF, GID

Data exchange with the MED and UNV formats

Project management tools and Software engineering workshop: ASTERIX

Command file editor and syntax analyser: EFICAS

Improved Command language: PYTHON

• Loops, tests, control structures…
• Method, class…
• Interactive calculations and visualisations (mathematics library, HMI, plotting…)

And let’s not forget...

Quality assured software (independent validation, 1400 reference test cases, 10 000 pages of documentation, source management, quality sheets and REX…, qualification of versions…)

Code-aster.org website (downloads, online documentation, forum, FAQ, examples…)

Communication and networks (term paper Aster-Echo, User Club with correspondence network and annual open day, open source Code_Aster under GPL license…)