Please note that this section is under revision and is not complete. Please contact CMT for updated recommendations.
This guide outlines in general terms the steps required to set-up and run a processing model in MSC.Marc/COMPRO. Some basic familiarity with MSC.Marc is assumed. The guide makes many references to MSC.Marc command cards (keywords) and only provides minimal detail on the commands. The MSC.Marc documentation should be consulted for complete details of each keyword.
Generally speaking, there are five steps associated with setting up and running a MSC.Marc analysis:
Note that due to how MSC.Marc is structured, a full process modelling simulation requires two analyses. First, the thermal problem must be solved, where the heat transfer, heat generation due to reaction, etc., is used to determine the temperature history of each integration point in the model. Next, the stress problem is solved, using the temperature history, and optionally the volume fraction history, to determine the displacements and stress due to the cure cycle. A different input file is required for each of these analyses. Note that as of this writing, flow analyses cannot be run with MSC.Marc and COMPRO CCA.
This two-step analysis is achieved by writing the temperature history to a separate file during the thermal analysis. This file is then used as the basis of the temperature history for the stress analysis.
Simplified analyses can be performed, in which just the thermal analysis is run (if the analysis is being run to determine exotherms, for example), or in which just the stress analysis is run (in this case ignoring any thermodynamic effects and assuming that the part is the same temperature as the air temperature, everywhere).
Create the geometry and element mesh in MSC.Patran or your favourite pre-processor. In the process modelling of composites, especially in 3D analyses, quite a bit of care and planning must be put into the pre-processing.
Warning
Currently, the mesh must be in either metres or inches, depending on your unit system (SI or USCS). If your mesh is in not in these units, the results will not be meaningful. Particularly, in USCS (Imperial), be certain that all units (including derived units) are in inches, pounds, Fahrenheit / Rankine, seconds, BTU, etc.
Very little modification of the MSC.Marc input file is required to invoke the CCA material models.
For thermal analyses, specify the material using the ANISOTROPIC card. The material ID must be a number greater than 1000 for CCA materials.
Note
The CCA library will assume that any material with an id greater than 1000 is a CCA material.
This number must correspond to the number specified in the cca-configuration.xml file for the given material. You must also ensure that the flag to call the user subroutine ANKOND is set to 1. Set the density and specific heat to 1.0, since these material properties will be set by the CCA libraries.
ANISOTROPIC $ mid, ankond flag 1000,1 $ density, Cp, emissivity 1.0,1.0,0. $ element list Part
For stress analyses, the material must be specified using the HYPOELASTIC card. As in thermal analyses, the material ID must be a number greater than 1000 for CCA materials, and must correspond to the number specified in the cca-configuration.xml file. You must ensure that the flag to call the user subroutines ANEXP and HYPELA2 are set to 1 and 3 respectively. Set the density to 1.0 and the CTE to 0.0 as these will be set by the CCA libraries.
HYPOELASTIC $ # of data sets, unit file # 1, $ MID, IUANEXP, IUHYPELA2, 1,1,3 $ rho (stress), CTE, K, Cp, R, rho (HT), E 1.,0., $ element list Part
The initial state of the elements must be specified. These statements set the initial values of the CCA state variables (see Table 2 at the end of section 3.1). Note that MSC.Marc reserves temperature as State Variable #1, so the state variable numbers in the INITIAL STATE cards are offset by +1 from the numbers shown in Table 2. Also, MSC.Marc cannot be used for flow analyses, so the largest state variable number is 6. Be certain to set the initial state for each state variable of each integration point in each element that has a CCA material, using method #4 (see the MSC.Marc documentation Vol C, Chapter 3):
INITIAL STATE 2,4,1, 0.001 Allelements 1 TO 8 ... INITIAL STATE 7,4,1, 0. Allelements 1 TO 8
In thermal analyses, the resin curing causes internal heat generation. This is captured in the user subroutines by invoking distributed fluxes through the DIST FLUXES card. For all elements containing user materials, specify a distributed flux of type 3, with a magnitude of 1.0 and a flux index of 1:
DIST FLUXES 1 3,1.0,1 Part
Also in thermal analyses, the temperatures can be applied directly using the FORCDT card in combination with programming the cure cycle in the marc.f file, or by specifying heat transfer coefficients using the FILMS card and programming the cure cycle in the marc.f file.
An example of specifying HTCs on a surface:
FILMS
1
5,2.0383E-5,1.,1,1
Bagside
The COMPRO Common Component Architecture has been implemented into MSC.Marc as a set of routines called by the user subroutines film, forcdt, hypela2, anexp, flux, ankond, uspcht, and others. MSC.Marc/COMPRO is distributed as two compiled object files that MSC.Marc combines with its own engine at run time. In Windows, these file are libcca.lib and cca-MarcInterface.lib. These object files must be placed in an appropriate directory prior to running your analysis. An appropriate location might be C:\MSC.Software\MSC.Marc\2005r3\lib.
Additionally, the MSC.Marc installation must be made aware of these additional libraries prior to running analyses. The file include.bat must be modified. Open this file in a text editor, and around line 235, there is a line that begins with:
SET SYSLIBS=%DYNAMICDLLS% /release /subsystem:console
Modify this line such that the two CCA libraries are referenced. If you placed the two LIB files in the lib directory, you can do this by adding %LIBDIR%\libcca.lib %LIBDIR%\cca-MarcInterface.lib to the end of the line. Typically this means that the line looks like (note that this is all on one line):
SET SYSLIBS=%DYNAMICDLLS% /release /subsystem:console /incremental:no /nodefaultlib:libc.lib /nodefaultlib:msvcrt.lib %IMAGEHLP_LIB% libmmt.lib libifcoremt.lib %LIBIRC_LIB% %LIBDIR%\libcca.lib %LIBDIR%\cca-MarcInterface.lib
The directory containing your MSC.Marc .dat file is your job directory. In this directory, you need the input files for the run, as well as the cca-configuration.xml file and the marc.f file (supplied in the installation package).
The marc.f file is a Fortan 77 file that is used to link MSC.Marc to the user subroutines. This file is also used to specify the temperature cycles through either the film subroutine (for specifying a time variant temperature sink on boundaries that are specified with the FILMS keyword) or the forcdt subroutine (for specifying absolute temperatures on nodes affected by the FORCDT keyword). This file must be edited with a text editor to specify the temperature cycle in one (or both) of these subroutines. The other subroutines in the file are essential for linking the CCA library to MSC.Marc and should not be modified.
The cca-configuration.xml file establishes the link between the material models selected in the MSC.Marc input file, and the CCA data files. It also sets some global parameters related to the run. The cca-configuration.xml file must be edited (as of this writing, with a text editor). The details of setting the CCA options can be found in Chapter 4 of the COMPRO Common Component Architecture User’s Guide.
Once these initial steps have been completed, the run can be started by typing something similar to the following at the command line:
run_marc.bat -j jobname -u marc.f -b n
If everything is working fine, then immediately after reporting the license checkout, you will see a boilerplate message:
**************************************************************************** * * * COMPRO Common Component Architecture * * * * Revision 631 (2007-05-28 11:45:41) UID: 1181067037 * * * * Convergent Manufacturing Technologies Inc. * * 6190 Agronomy Road, Suite 403 * * Vancouver, British Columbia, Canada * * support@convergent.ca or http://www.convergent.ca * * * ****************************************************************************
If this message is not displayed, then the CCA libraries have not been properly integrated into MSC.Marc.