Beam 3-point bending (Connector Abaqus)
The original input and output files can be found with the examples of COSSAN, in the folder containing the files related to finite element model.
The nodal displacement are printed in the beam.dat file using the following commands:
*NODE PRINT U, *EL PRINT S, *EL FILE S, *NODE FILE U
Inputs dedicated to Abaqus
For the analysis using Abaqus, functions dedicated to the shear modulus of the material and to the inertia moments and area of the beam have to be created (in the Inputs section of COSSAN-X).
The function dedicated to the shear modulus is named shear, its expression is:
The function dedicated to the inertia moment of the beam with respect to the direction of the applied force is named Inertia11, its expression is:
The function dedicated to the inertia moment of the beam with respect to the direction perpendicular to the applied force is named Inertia22, its expression is:
The function dedicated to the torsion inertia moment of the beam Inertia_torsion, its expression is:
Running Abaqus (Interaction)
The command line used to run Abaqus should be written in the following form:
/Apps/abaqus/Commands/abq6133 job=<file name>.inp interactive
Bearing in mind that the file format must include the extension *.inp as shown.
The generated output file format is usually with the extension *.dat.
Then, the configuration window in COSSAN-X under Evaluators, Connectors should be like the following:
A new connector is created. The following figure shows the wizard for creation of Connector.
The finite element solver is selected among the different configuration available, which have been initially predefined.
Click then on Finish. The following window appears:
The following actions need to be performed.
Import solver files in the project
All the input files requires by the finite element software and all the files which are written by the finite element software are imported into the COSSAN-X project. All the files are handled in the section File management, which displays the currently available files. The files are imported one by one by clicking on Import file, or the content of a directory is imported by clicking on Import directory.
All the files necessary to successful execution of the finite element codes have to be imported. In this example, only the the ASCII input file is necessary.
The use of these file is specified below.
Define Input files
All the input files (and the files necessary to successful execution of the finite element codes) are specified in the Input category.
The input file format allows partial colouration of the ASCII input file specific to the finite element solver.
The main input file is used in the definition of the connector. Its name will be automatically used by the connector while calling the finite element solver (see Connector_(editor)).
The input files consists of all file that will be copied to the execution folder. The files that require to be modified by COSSAN-X are selected by activating the check-box left to the file name. The extension .cossan is automatically and temporary added to this files. These files are used to define new Injectors, in order to inject values from COSSAN-X (realizations of the Random variables,...).
Define output files
All the output files used to recover quantities of interest are specified in the Output category.
The output file will be used to define extractors, retrieving results from the simulations.
In the case of this example, the connector editor look as following after all the input and output files have been specified. The names of the files might have to be changed in order to match the definition of the connector and the version of the finite element software.
Identifiers are set in order to inject the quantities of interest at the right position in the input file. In this example, identifiers are defined for the cross section, the inertia moment of the beam, the material properties and the point force.
The properties of the identifiers needs to be set so that the values are properly replaced (same number of characters as in the original file, etc). The name of each identifier is identical to the name of the object to inject.
The extractor is used to retrieve the quantity of interest. In this example this is the vertical displacement at the mid-point of the beam, that is to say the displacement of node 21 in the y-direction.
First an anchor is defined at the header of the table of the nodal displacements. Then an identifier is set at the position of the quantity of interest in the output file. The response properties have to be set: only one value is extracted, it will be given the name u_y.
The response has to be linked to the anchor by dragging it.