3. Modeling A#

3.1. Workflow of the TP#

The aim is to conduct the calculation by modeling the concrete using elements \(3D\) and the steel reinforcements with elements GRILLE_MEMBRANE. The*Code_Aster* command file will be generated using AsterStudy.

3.2. Realization of the mesh#

Limited time option: we suggest reading the mesh (forma40a.mmed) that was created with a Salomé script. The file can be retrieved from the salome_meca installation directory (path: XXX /salome_meca/ VYYY /tools/code_aster_stable_ ZZZZ /share/aster/tests).

Option in an unconstrained time: the user can perform the mesh, making sure to pass the mesh through the surfaces where the reinforcement sheets are located.

3.3. Elastic calculation#

The aim is to define the file the command file used to carry out this study. The various steps are indicated below:

Read the mesh in MED (LIRE_MAILLAGE) format.

Assign models to different mesh groups (AFFE_MODELE/3D and GRILLE_MEMBRANE).

Define the characteristics of the structural elements (AFFE_CARA_ELEM, keyword GRILLEpour the elements GRILLE_MEMBRANE), namely the section and the coordinate system used to define the local coordinate system.

Define the material properties of steel and concrete (DEFI_MATERIAU) and affect them (AFFE_MATERIAU).

Create time discretization using DEFI_LIST_REEL.

Define boundary conditions and loads (AFFE_CHAR_MECA, keywords DDL_IMPOet PESANTEUR). Note: loading on edge \(B1X\) requires defining a multiplier function using the DEFI_FONCTION command that will be applied to loading via the FONC_MULT keyword under EXCIT or using AFFE_CHAR_MECA_F.

Use STAT_NON_LINEpour the elastic calculation (COMPORTEMENT/RELATION =” ELAS “) with the instant list defined earlier.

Print the result in MED format (IMPR_RESU/FORMAT =” MED “).

Save and start the calculation.

3.4. Post-treatment#

3.4.1. Basic stripping with Paravis#

Import file MED in*Salomé* under Paravis.

Trace the deformed (Warp by Vector filter).

Visualize constraints at Gauss points (filter ELGA field To Point Gaussian).

Complete the command file by calculating various interesting quantities: deformations (type ELGAou ELNO), stresses and/or equivalent deformations. Start the calculation again and then visualize the different quantities under Salomé.

3.4.2. Plotting a force-displacement curve in Code_Aster#

By using the initial command file or by defining a new stage, do the post-processing to draw the force-displacement curve.

Calculate nodal forces using command CALC_CHAMP.

Retrieve the result of the efforts applied using the POST_RELEVE_T command.

Retrieve the next move \(>\) from edge \(NO2NO3\) using the POST_RELEVE_T command.

Print both tables to visualize the information contained.

Plot the force-displacement curve in XMGRACE format using the IMPR_FONCTION command. To do this, retrieve the functions to be traced using RECU_FONCTION by applying the necessary filters. (Do not forget to specify the unit and define the output file to be able to visualize the curve directly).

3.4.3. Suggestions for other post-treatments#

Retrieve the deformations along a line (for example, from point \((\mathrm{0,2.5}\mathrm{,0})\) to point \((10\text{.}\mathrm{,2}\text{.}5\mathrm{,0})\)) using the command MACR_LIGN_COUP. Print the curve using command IMPR_TABLE.

Print the maximum stress obtained in concrete and then in steels using the POST_RELEVE_T command (OPERATION =” EXTREMA “).

3.5. Tested sizes and results#

Value of stress components:

Location

Identification

Reference

Tolerance

Edge \(B1X\)

Resulting effort \(DZ\)

\(\mathrm{3,16529}\times {10}^{5}\)

:math:`mathrm{0,001}`%

Maximum stress in the steel sheet \(ACM\)

\(\mathrm{2,70282}\times {10}^{6}\)

:math:`mathrm{0,001}`%

Maximum stress in concrete

\(\mathrm{1,61016}\times {10}^{7}\)

:math:`mathrm{0,001}`%