ABAQUS Analysis User's Manual  


7.9.4 Executing the coupled analysis

Products: ABAQUS/Standard  ABAQUS/Explicit  

Reference

Overview

The options for execution of a coupled analysis can vary considerably. In general, you will run

  • the MpCCI server,

  • the ABAQUS analysis, and

  • the third-party analysis.

In most cases you will find it easiest to use the MpCCI Graphical User Interface (GUI) to define the MpCCI configuration file and to control the startup of the server and client applications. In rare circumstances you will need to edit the MpCCI configuration file and start the server and analysis codes yourself.

MpCCI GUI overview

This section provides a brief overview of the MpCCI GUI and is intended to provide you with a sense of the functionality that the GUI provides. For additional details on the GUI or for details on how to execute a coupled analysis without using the GUI, consult the MpCCI User's Manual. The descriptions and figures that follow are based on the version of MpCCI, Version 3.0, available at the time of publication of this manual; later versions of MpCCI may vary from the description here.

The MpCCI GUI will guide you through a number of steps to

  • select the analysis codes and the respective input files for the coupled simulation,

  • define the interface regions on which data will be exchanged,

  • define the MpCCI control parameters, and

  • submit the jobs for co-simulation analysis.

All of the configuration settings that you make in this process can then be saved in MpCCI configuration files for subsequent runs.

Selecting the analysis codes and respective input files

When you first start the MpCCI GUI, the Models tabbed page, shown in Figure 7.9.4–1, is displayed.

Figure 7.9.4–1 Selecting the analysis applications and input files (courtesy of Fraunhofer SCAI).

On the Models tabbed page you select the analysis codes that will participate in the coupled simulation. For each analysis code you select the input file and run the appropriate code scanner. The code scanner parses the input file to determine analysis parameters and the interface regions if they are currently defined. The file scanner for ABAQUS scans the ABAQUS input file and searches for a co-simulation analysis step. If the *CO-SIMULATION option is located, the file scanner reads the defined interface surfaces and uses these surfaces for subsequent data input. If the *CO-SIMULATION option is not found, the file scanner reads all of the surface definitions and uses these definitions for subsequent data input. The MpCCI GUI may change the ABAQUS input file by adding or modifying the *CO-SIMULATION option.

After defining the models and scanning the input files, click Next to advance to the Coupling tabbed page.

Defining coupling pairs

The Coupling tabbed page contains several tabbed pages, shown in Figure 7.9.4–2, where you specify the coupling by pairing regions (for example, ABAQUS surfaces or FLUENT components) and defining the solution quantities that will be exchanged for each interface region.

Figure 7.9.4–2 Defining coupling pairs on the Face (2D) tabbed page (courtesy of Fraunhofer SCAI).

For each solution quantity you identify which analysis code sends the quantity and which analysis code receives the quantity. Choices are limited to the appropriate solution quantities for each code. If the *CO-SIMULATION option is not specified in the ABAQUS input file, the MpCCI GUI will generate the appropriate *CO-SIMULATION options.

After completing the coupling definition, click Next to advance to the Edit tabbed page.

Defining MpCCI parameters

On the Edit tabbed page, shown in Figure 7.9.4–3, you can modify any of the default MpCCI settings. These settings control the search algorithms, solution mapping schemes, and behavior of the MpCCI server. For further details, consult the MpCCI User's Manual.

After modifying the MpCCI settings, click Next to advance to the Go tabbed page.

Figure 7.9.4–3 Modifying default MpCCI settings (courtesy of Fraunhofer SCAI).

Running the jobs

On the Go tabbed page, shown in Figure 7.9.4–4, you provide specific information about starting the analysis codes; in the case of the ABAQUS analysis you set the executable, memory parameters, number of processors, and other parameters. Most of these parameter settings are available for convenience in the GUI; alternatively, you can specify these settings in the ABAQUS environment file (see “Using the ABAQUS environment settings,” Section 3.4.1).

Figure 7.9.4–4 Defining additional parameters (courtesy of Fraunhofer SCAI).

You can start the MpCCI server and each of the analysis codes from the MpCCI GUI by clicking Start. You can monitor the ABAQUS job by inspecting the message file, which will include messages identifying the increments at which coupling occurs, as well as by reviewing the results in the Visualization module of ABAQUS/CAE.

ABAQUS job execution will occur in the directory where the ABAQUS input file is located. Job parameters not set in the GUI will be determined according to normal ABAQUS conventions (see “Execution procedure for ABAQUS/Standard and ABAQUS/Explicit,” Section 3.2.2).

Starting a co-simulation without the MpCCI GUI

In rare circumstances you will need to start the MpCCI server and the analysis codes outside the MpCCI GUI. Please consult the MpCCI User's Guide on how to specify the MpCCI configuration file and start the MpCCI server.

To execute a coupled analysis from the command prompt window:

  1. Initialize the command (or shell) window by executing the ccienv script found in the config directory under the MpCCI installation directory.

  2. Start the MpCCI server with the ccirun script found in the bin directory of the MpCCI installation directory. For example, use 

    ccirun –idstring –server –log –o example example.cci
    where example.cci is the name of the MpCCI configuration file to start the server.

  3. Start the ABAQUS analysis and the third-party analysis in the directories specified in the MpCCI configuration file. Start the ABAQUS analysis as you would any other ABAQUS analysis job. ABAQUS will contact the MpCCI server at the beginning of the co-simulation analysis step. The order in which the analysis jobs are started does not matter.

Running ABAQUS in parallel

You can run an ABAQUS analysis in parallel in conjunction with the co-simulation capability. See “Parallel execution in ABAQUS/Standard,” Section 7.19.2, and “Parallel execution in ABAQUS/Explicit,” Section 7.19.3, for details on running an ABAQUS analysis in parallel. The number of CPUs used in the ABAQUS analysis must be consistent with the number specified in the MpCCI configuration file. This MpCCI configuration parameter can be set through the MpCCI GUI.

Resource requirements

The following software is required:

  • MpCCI Version 3.0. MpCCI is distributed and licensed by Fraunhofer SCAI. For contact information, refer to http://www.scai.fraunhofer.de.

  • The Message Passing Interface (MPI) library. The version of MPI depends on the platform and operating system; consult the MpCCI Installation Manual for details.

  • Java, required by the MpCCI GUI.

  • Perl, required by the analysis code input scanner.

  • The remote procedure protocol or the secure shell, required to run a simulation across multiple platforms. For further information, consult the MpCCI Installation Manual.