2.4 Checking the input data

Having generated the input file for this simulation, you are ready to run the analysis. Unfortunately, it is possible to have errors in the input file because of typing errors or incorrect or missing data. You should perform a datacheck analysis first before running the simulation. To run a datacheck analysis, make sure that you are in the directory where the input file frame.inp is located, and type the following command:

abaqus job=frame datacheck interactive

If this command results in an error message, the ABAQUS installation on your computer has been customized. You should contact your systems administrator to find out the appropriate command to run ABAQUS. The job=frame parameter specifies that the jobname for this analysis is frame. All the files associated with this analysis will have this jobname as their identifier, which allows them to be recognized easily.

The analysis will run interactively, and messages similar to those shown below will appear on your screen:

ABAQUS JOB frame
Begin Analysis Input File Processor
11/11/2004 11:34:58 AM
Run pre.exe
ABAQUS License Manager checked out the following licenses:
ABAQUS/Foundation checked out 3 tokens.
11/11/2004 11:35:00 AM
End Analysis Input File Processor
Begin ABAQUS/Standard Datacheck
Begin ABAQUS/Standard Analysis
11/11/2004 11:35:00 AM
Run standard.exe
ABAQUS License Manager checked out the following licenses:
ABAQUS/Foundation checked out 3 tokens.
11/11/2004 11:35:03 AM
End ABAQUS/Standard Analysis
ABAQUS JOB frame COMPLETED

When the datacheck analysis is complete, you will find that a number of additional files have been created by ABAQUS. If any errors are encountered during the datacheck analysis, messages will be written to the data file, frame.dat. This data file is a text file that can be viewed in an editor or printed. Part of this data file is shown in Figure 2–8 through Figure 2–12.

Try viewing the data file in a text editor. The file can contain lines up to 256 characters long, so the editor should be able to accommodate that many characters. At the top of the file is a header page that contains information about the version of ABAQUS used to run the analysis. The header page also contains the phone number, address, and contact information of your local ABAQUS office or representative who can offer technical support and advice.

Following this header page is an echo of the input file (Figure 2–8). The input data echo is generated by adding the option *PREPRINT, ECHO=YES to the input file. By default, the parameter ECHO is set to NO.

Figure 2–8 Input file echo in the data file.

Following the input data echo is a list of the options processed by ABAQUS (Figure 2–9). This is the first point at which error and warning messages appear. All error messages are prefixed with ***ERROR, while warnings begin with ***WARNING. Since these messages always begin the same way, searching the data file for warning and error messages is straightforward. When the error is a syntax problem (i.e., when ABAQUS cannot understand the input), the error message is followed by the line from the input file that is causing the error.

Figure 2–9 List of options processed by ABAQUS.

The rest of the data file is a series of tables containing all of the model data (Figure 2–10) and the history data (Figure 2–11) that should be checked for any obvious errors or omissions. These tables are generated by including the option *PREPRINT, MODEL=YES, HISTORY=YES in the input file. However, these tables may take up a large amount of disk space for large models. By default, the parameters MODEL and HISTORY are set to NO.

Figure 2–10 Model data in data file.

Figure 2–11 History data in data file.

If there are any error messages, the number of such messages produced during the datacheck analysis is listed at the end of the data file. If there are only warning messages, the number of these messages is listed at the bottom of the data file after any of the requested output.

If error messages are generated during the datacheck analysis, it will not be possible to perform the analysis until the causes of the error messages are corrected. The causes of warning messages should always be investigated. Sometimes, warning messages are indications of mistakes in the input data; other times they are harmless and can be ignored safely.

Finally, there is a summary of the size of the numerical model and an estimate of the file sizes required for the simulation (Figure 2–12). When analyzing large models, use this output to ensure that you have enough disk space available to perform the analysis.

Figure 2–12 Summary of problem and file sizes.