4.1.1 Output

Products: ABAQUS/Standard  ABAQUS/Explicit  ABAQUS/CAE  

References

Overview

ABAQUS can create the following output files during an analysis:

  • a data file containing printed output of the model and history definition generated by the analysis input file processor and, in ABAQUS/Standard, printed output of results written during the analysis run;

  • an output database file containing results for postprocessing with the Visualization module of ABAQUS/CAE (ABAQUS/Viewer) and, in ABAQUS/Standard, diagnostic information;

  • a selected results file in ABAQUS/Explicit;

  • a results file containing results for postprocessing with external software (in ABAQUS/Explicit this file is generated by converting the selected results file);

  • a message file containing diagnostic messages about the solution; and

  • a status file containing information about the status of the analysis and, in ABAQUS/Explicit, diagnostic messages and information about the stable time increment.

ABAQUS can create files for restarting an analysis—see Restarting an analysis, Section 9.1.1. In ABAQUS/Standard these files can also be used to extract results output not requested during an analysis.

The data file

The data file (job-name.dat) is a text file that contains information about the model definition (generated by the analysis input file processor) and, in ABAQUS/Standard, tabular output of results. The analysis input file processor information includes the model definition, the history definition, and messages identifying any error and warning conditions that were detected while processing the input data.

Controlling the amount of analysis input file processor information written to the data file

You can control the amount of information written to the data file by the analysis input file processor.

Input File Usage:           Use the following option in the model definition section of the input file:
*PREPRINT

ABAQUS/CAE Usage: 

Job module: job editor: General: Preprocessor Printout


Input file echo

By default, the input file will not be echoed to the data file. You can choose to activate this printout. If the input file is defined in terms of an assembly of part instances, the echo to the data file will be that of the flattened input file (i.e., one that does not use parts and assemblies).

Input File Usage:           
*PREPRINT, ECHO=YES or NO

ABAQUS/CAE Usage: 

Job module: job editor: General: Preprocessor Printout: Print an echo of the input data


Input parameter information

For parametrized input files, information about input parameters and their values can be printed in the data file. By default, the modified version of the original input file showing this information will not be printed in the data file. You can choose to activate this printout.

Input File Usage:           
*PREPRINT, PARVALUES=YES or NO

ABAQUS/CAE Usage: Parametrized input files are not supported in ABAQUS/CAE.

Parameter-free input file information

For parametrized input files, a parameter-free version (after parameter evaluation and substitution) of the original input file can be printed in the data file. By default, this modified version of the input file will not be printed in the data file. You can choose to activate this printout.

Input File Usage:           
*PREPRINT, PARSUBSTITUTION=YES or NO

ABAQUS/CAE Usage: Parametrized input files are not supported in ABAQUS/CAE.

Model and history definition summaries

By default, the options defining the model and history data will not be summarized in the data file. You can choose to activate this printout.

Input File Usage:           
*PREPRINT, MODEL=YES or NO, HISTORY=YES or NO

ABAQUS/CAE Usage: 

Job module: job editor: General: Preprocessor Printout: Print model definition data and Print history data


Contact constraint information

In ABAQUS/Standard you can choose to activate printout of detailed information about the contact constraints generated by the contact pair definition data.

Input File Usage:           
*PREPRINT, CONTACT=YES or NO

ABAQUS/CAE Usage: 

Job module: job editor: General: Preprocessor Printout: Print contact constraint data


Requesting printed results

In ABAQUS/Standard the values of output variables can be printed to the data file in tabular format throughout the analysis. You can control the following types of printed output during the analysis run: element output, node output, contact surface output, energy output, fastener interaction output, modal output, section output, and radiation output—see Output to the data and results files, Section 4.1.2, and Cavity radiation, Section 32.1.1. You specify the variables to be printed in each output table and, for element variables, the locations at which they are to be printed (at the integration points, at the element centroid, at the nodes, or averaged at the nodes). Nodal variables at nodes with transformations can be written in either the global or the local coordinate system (see Transformed coordinate systems, Section 2.1.5). The list of available variables is given in ABAQUS/Standard output variable identifiers, Section 4.2.1. Output of results to the data file is requested as part of a step definition.

Viewing part and assembly information in the data file

An ABAQUS model can be defined in terms of an assembly of part instances (see Defining an assembly, Section 2.9.1). In such a model node and element numbers can be repeated within the definitions of different parts. These local numbers are converted internally by ABAQUS to unique global numbers, and the output written to the data file is given in terms of those internal numbers. A map between user-defined numbers and internal numbers is printed to the data file (after the step data) if any output that includes node and element numbers is requested in the data file.

Set and surface names that appear in the data file are prefixed by the assembly and part instance names, separated by underscores (Assembly_Part1–1_setname, for example).

Local coordinate systems defined within a part or part instance are translated and rotated according to the positioning data given in the part instance definition.

The output database

The ABAQUS output database (job-name.odb) is a neutral binary file used to store model information and analysis results in terms of an assembly of part instances. The Visualization module of ABAQUS/CAE (ABAQUS/Viewer) uses the output database for postprocessing analysis results and viewing diagnostic information.

Requesting output to the output database

You choose the variables to be written to the output database from the lists in ABAQUS/Standard output variable identifiers, Section 4.2.1, and ABAQUS/Explicit output variable identifiers, Section 4.2.2. The following types of output are available: element output, node output, contact surface output, energy output, integrated output, time incrementation output, fastener interaction output, modal output, and radiation output. In addition, a subset of the diagnostic information that is written to the ABAQUS/Standard message file (see “The message file”) is included in the output database. See Output to the output database, Section 4.1.3, for a detailed explanation of how to generate output database requests.

Three types of information are stored in the output database: “field” output, “history” output, and diagnostic information. Field output is intended to be relatively infrequent output for a large portion of the model. ABAQUS/CAE uses field output to generate contour plots, displaced shape plots, symbol plots, and X–Y plots in the Visualization module. History output is intended to be output for a small portion of the model requested at a fairly high frequency. ABAQUS/CAE uses history output to generate X–Y plots in the Visualization module. See Output to the output database, Section 4.1.3, for detailed descriptions of field and history output. Diagnostic information is intended to provide convergence information for use in ABAQUS/CAE; for more information, see Chapter 23, Viewing diagnostic output,” of the ABAQUS/CAE User's Manual.

Format of the output database

The output database is a neutral binary, platform-independent file. Unlike the restart or binary results files, it can be copied directly from one computing platform to another without translation.

By default, floating point data are written to the output database file in single precision. You can choose to write floating point nodal output data to the output database file in double precision; see Execution procedure for ABAQUS/Standard and ABAQUS/Explicit, Section 3.2.2, for details.

You can open an output database file from an older version of ABAQUS in ABAQUS/CAE, with the exception that Version 5.8 output database files cannot be opened in Version 6. Output database files from previous versions of ABAQUS must be converted to the current version when they are opened. If you are using an older version of ABAQUS/CAE, you cannot open an output database file created from a newer version of ABAQUS.

The selected results file

The ABAQUS/Explicit selected results file (job-name.sel) stores user-selected results, which are converted into the results file (job-name.fil) for postprocessing by other commercial postprocessing packages.

Element output, node output, and energy output can be requested (see Output to the data and results files, Section 4.1.2, for details); the variables available for output are listed in ABAQUS/Explicit output variable identifiers, Section 4.2.2. You can write a user-selected subset of the results for a given node set or element set at more frequent intervals than the restart intervals. You specify the output requests within a step definition, which allows you to be selective about the amount of data written to the selected results file to avoid using excessive disk storage. For example, when dealing with a very large model, you may choose to write only the current displacements and the equivalent plastic strain for the entire model 20 times in the step and to write the acceleration history at one node 200 times in the step.

The results file

The ABAQUS results file (job-name.fil) can be read by external postprocessors to produce X–Y plots or printed tabular output. Most commercial finite element results-display packages provide translators that use the ABAQUS results file as their input. The results file can also be used as a convenient medium for importing analysis results into your own postprocessing program. Accessing the results file information, Section 5.1.3, provides details on how to read this file.

Results file output of temperature from a heat transfer or thermal-electrical analysis can be used as input to a stress analysis of the same mesh (see Sequentially coupled thermal-stress analysis, Section 6.5.3).

Obtaining results file output in ABAQUS/Standard

In ABAQUS/Standard you choose the variables to be written to the results file from the lists in ABAQUS/Standard output variable identifiers, Section 4.2.1, in a manner similar to that for output printed to the data file. You must specifically request that values be written to the results file or none will be provided. Element output, node output, contact surface output, energy output, modal output, and radiation output are available—see Output to the data and results files, Section 4.1.2, and Cavity radiation, Section 32.1.1, for details.

Obtaining results at the beginning of a step

You can request that the solution state at the beginning of a step (the zero increment) be written to the ABAQUS/Standard results file. Zero-increment file output is available only for steps in which the concept of time governs the incrementation scheme of the selected procedure and, hence, the following procedures are excluded:

If you request zero-increment results file output, it will be generated for all valid procedures in a given analysis.

You must request zero-increment results file output to generate a zero-increment results file in a data check analysis (see Execution procedure for ABAQUS/Standard and ABAQUS/Explicit, Section 3.2.2). It is strongly recommended that you request zero-increment results file output if the results file is used to drive a submodel; see Submodeling, Section 10.2.1, for further discussion.

Input File Usage:           
*FILE FORMAT, ZERO INCREMENT

The *FILE FORMAT option can be given as model data or as history data, but it can appear only once in the input file.

ABAQUS/CAE Usage: Results file output cannot be requested in ABAQUS/CAE.

Obtaining results file output in ABAQUS/Explicit

The ABAQUS/Explicit results file is a sequential access file generated from the selected results file (see Execution procedure for ABAQUS/Standard and ABAQUS/Explicit, Section 3.2.2). The results file contains the requested results in the format described in Results file output format, Section 5.1.2.

Input File Usage:           Use either of the following command line options to convert a selected results file to a results file:

abaqus job=job-name convert=select

abaqus job=job-name convert=all


ABAQUS/CAE Usage: The selected results file cannot be converted in ABAQUS/CAE.

Part and assembly information

An ABAQUS model can be defined in terms of an assembly of part instances (see Defining an assembly, Section 2.9.1). However, the results file does not contain part and assembly records.

In a model defined in terms of an assembly of part instances, node and element numbers can be repeated within the definitions of different parts. These local numbers are converted internally by ABAQUS to unique global numbers, and the output written to the results file is given in terms of the global (internal) numbers. A map between user-defined numbers and internal numbers is printed to the data file if any results file output that includes node and element numbers is requested.

Set and surface names that appear in the results file are prefixed by the assembly and part instance names, separated by underscores (Assembly_Part1–1_setname, for example).

Local coordinate systems defined within a part or part instance are translated and rotated according to the positioning data given in the part instance definition.

Format of the results file

The ABAQUS results file is organized as a sequential file, in binary or in ASCII format. ASCII format is necessary if the file is to be read on a computer system that is different from the one on which the file was written. ASCII format allows the results file to be transferred between different computer systems without having to translate binary data. ASCII format is not needed if the file will always be used on the same system or on systems that use the same binary format. If the results file output will always reside on the same computer, the default binary format is usually the most efficient way of storing the file. For large problems a file in ASCII format will be significantly larger than the same file in binary format.

Controlling the format of the results file in ABAQUS/Standard

ABAQUS/Standard can write the results file in either binary or ASCII format. The default format is binary.

The results file output must be written in the same format for the entire analysis. The format cannot be changed upon restarting the problem.

The format of the ABAQUS/Standard results file can also be controlled in the ABAQUS/Standard environment file (see Using the ABAQUS environment settings, Section 3.3.1). The format specified in an analysis supersedes the value defined in the enviroment file.

In addition, the ascfil facility in the ABAQUS execution procedure (Execution procedure for ASCII translation of results (.fil) files, Section 3.2.9) can be used to convert a binary ABAQUS/Standard results file (job-name.fil) to ASCII format (job-name.fin) after the analysis completes.

Input File Usage:           
*FILE FORMAT, ASCII

The *FILE FORMAT option can be given as model data or as history data, but it can appear only once in the input file.

ABAQUS/CAE Usage: Results file output cannot be requested in ABAQUS/CAE.

Controlling the format of the results file in ABAQUS/Explicit

ABAQUS/Explicit always writes the results file output in binary format during file conversion, but the binary ABAQUS/Explicit results file can be converted to ASCII format using the ascfil facility (Execution procedure for ASCII translation of results (.fil) files, Section 3.2.9).

ASCII format

Results file output format, Section 5.1.2, defines the contents of the records that are written to the results file; these descriptions also hold if the results file is written in ASCII format. All the data items in these files are either integers, floating point numbers, or character strings. When ASCII format is requested, each data item is translated into an equivalent character string before it is written to the file. These strings are written in 80-character logical records in the order described in the record definitions.

Each 80-character logical record is completely filled before the next one is started, so that any data item can be split, with some of the characters that define the item in one logical record and the remainder in the next. Each data item usually follows immediately behind its predecessor. The exception is that for results file record key 2001 ABAQUS will fill out the logical record with blank characters, so that the record can be written immediately to the physical storage medium. ABAQUS then inserts a logical record consisting of 80 blanks, which allows the end-of-file to be handled correctly.

The beginning of each “record” is indicated by an asterisk (*). Each floating point number begins with the character D, followed by the number in the format E22.15 or D22.15, depending on whether the version of ABAQUS that wrote the results file is a single or a double precision version. Each character string begins with the character A, followed by eight characters (if the character string has fewer than eight characters, the right part of the string is blank; character strings longer than eight characters are written eight characters at a time). Each integer begins with the character I, followed by a two digit integer giving the number of decimal digits in the integer, followed by the integer itself (written as decimal digits).

For example, record key 1900 for an S4R element with element number 5 and nodes 195, 198, 205, and 204 would be written

*I 18I 41900I 15AS4R     I 3195I 3198I 3205I 3204
and record key 101 for node 135 and 6 degrees of freedom would be written
*I 19I 3101I 3135D1.280271914214298E-10D1.500000000000036E+00
D-1.074629835784448E-46D 6.983222716550941E-12
D-4.084928798492785E-13D-1.072688441364597E-10

Precision of floating point data in the results file

The precision of floating point data written to the results file depends on the precision of the executable that generates the data. ABAQUS/Standard always uses double precision; thus, floating point data are always written to the ABAQUS/Standard results file in double precision. ABAQUS/Explicit can be run in single or double precision on most machines; see Procedures: overview, Section 6.1.1, for details on the precision level of the ABAQUS/Explicit executable. If the double precision executable for ABAQUS/Explicit is used, floating point data are written to the ABAQUS/Explicit results file in double precision; likewise, if the single precision executable for ABAQUS/Explicit is used, floating point data are written to the ABAQUS/Explicit results file in single precision.

Maximizing the efficiency of the results file

In ABAQUS/Standard each element output request (a collection of identifying keys entered on a single line) is preceded by an “element header” record (see Results file output format, Section 5.1.2). Hence, the size of the results file can be minimized by entering all element output variables of the same “type” (element integration point variable, element section variable, whole element variable, etc.) on a single line. (See Output to the data and results files, Section 4.1.2, for an explanation of the output variable types.) Consolidating output variable entries is encouraged, since it will reduce the size of the results file.

Example

For example, the following output requests can be used to request output of element variables in the results file in a stress/displacement analysis:

*EL FILE
 S, SINV, E, PE, CE, EE, ENER, TEMP, FV, COORD
 SF, SE
 LOADS, ELEN, EVOL
*EL FILE, REBAR
 S, SINV, E, PE, CE, EE, RBFOR, RBANG
 SF, SE
 LOADS, ELEN
(The output requests for rebar quantities need not be the same as the underlying element output requests.)

The message file

The message file (job-name.msg) is a text file that contains diagnostic messages about the progress of the solution.

The ABAQUS/Standard message file

In ABAQUS/Standard the message file contains diagnostic or informative messages about the progress of the solution. If any of these messages describe errors or warnings, the number of such errors or warnings is also given at the end of the data file. The message file is written automatically during an ABAQUS/Standard analysis.

The ABAQUS/Standard message file contains information about the increment number, step time, fraction of a step completed, equilibrium iterations, severe discontinuity (contact) iterations, plasticity algorithms, adaptive mesh smoothing, the load proportionality factor in a Riks analysis, etc. A portion of the diagnostic information in the message file is also written to the output database for use in ABAQUS/CAE (for more information, see Requesting diagnostic information” in “Output to the output database, Section 4.1.3).

You can control the amount of information written to the message file for each step. This feature is sometimes helpful in difficult analyses since it allows detailed diagnostic information to be written about certain events (such as contact) during a nonlinear solution; this information can often be useful in developing a strategy for the solution of highly nonlinear problems.

Input File Usage:           
*PRINT

The *PRINT option can appear only once within a step definition.

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print


Controlling the frequency of output to the message file

You can control the frequency at which information is printed to the message file by specifying the desired output frequency in increments. The default output frequency is 1 (or 10 in a direct cyclic analysis). The output will always be printed at the last increment of each step unless you specify a frequency of zero to suppress the output.

Input File Usage:           
*PRINT, FREQUENCY=N

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: Frequency N


Requesting detailed contact printout

You can obtain a detailed printout of contact conditions during iteration. This information about which points are contacting or separating in interface and gap problems is useful in tracking the development of the solution in difficult contact problems. The details are written for every severe discontinuity iteration. By default, the detailed contact output is suppressed.

Input File Usage:           
*PRINT, CONTACT=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Contact


Requesting detailed model change printout

You can obtain a detailed printout of model change operations (removal and reactivation) at the start of a step. This information includes the new original coordinates and normals of elements being reactivated strain free in a large-displacement analysis. By default, the detailed model change output is suppressed. See Element and contact pair removal and reactivation, Section 11.2.1, for details on model change operations.

Input File Usage:           
*PRINT, MODEL CHANGE=YES or NO

ABAQUS/CAE Usage: Model change output to the message file is not supported in ABAQUS/CAE.

Requesting detailed printout of problems with the plasticity algorithms

You can activate printout of element and integration point numbers for which the plasticity algorithms have failed to converge during an iteration. This information is useful for finding the place in the mesh and/or the plasticity model at which ABAQUS is encountering material model difficulties. Modeling problems and material parameter specification problems can be identified using this detailed printout. By default, this printout is suppressed.

Input File Usage:           
*PRINT, PLASTICITY=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Plasticity


Requesting output of equilibrium residuals

By default, equilibrium residuals during equilibrium iterations are output. You can choose to suppress this output entirely, but it is not recommended; without the output of equilibrium residuals, you cannot see the accuracy of the iteration process.

Input File Usage:           
*PRINT, RESIDUAL=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Residual


Requesting solver information

You can request information about the number of equations being solved and the required memory for each iteration. By default, solver output is suppressed.

Input File Usage:           
*PRINT, SOLVE=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Solve


Requesting detailed adaptive mesh smoothing printout

You can activate detailed printout of adaptive mesh smoothing in ABAQUS/Standard. The output includes information about the magnitude of the maximum displacement and the node and degree of freedom where the maximum displacement increment occurs during each mesh sweep. It also provides the node numbers at which geometric feature changes occur. By default, only a summary is output.

Input File Usage:           
*PRINT, ADAPTIVE MESH=YES or NO

ABAQUS/CAE Usage: Adaptive mesh output to the message file is not supported in ABAQUS/CAE.

Monitoring a degree of freedom in the message file

You can write the current value of a specified point and degree of freedom to the message file. This information can be used to monitor the progress of the solution. The information will also be written in the status file (see below). You can control the frequency at which the value is printed in the message file. The default frequency is 1 (or 10 in a direct cyclic analysis).

Degree of freedom monitoring does not apply to eigenvalue buckling prediction, eigenfrequency extraction, or response spectrum procedures. For other linear perturbation procedures output for the monitored degree of freedom is the base state value.

Input File Usage:           
*MONITOR, NODE=node_number, DOF=dof, FREQUENCY=N

The node and degree of freedom being monitored can be changed from step to step by repeating the *MONITOR option. The node and degree of freedom specified in the last occurrence of this option in a step will be used for that step.

ABAQUS/CAE Usage: 

Step module: OutputDOF Monitor: Monitor a degree of freedom throughout the analysis, click Edit to select the point, Degree of freedom: dof, Print to the message file every N increments


In ABAQUS/CAE only one point and degree of freedom can be monitored for an analysis; you cannot change the monitor request from step to step.

The ABAQUS/Explicit message file

In ABAQUS/Explicit the message file contains messages if potential problems are detected during an analysis. You can control the output of diagnostic messages for each step (see Explicit dynamic analysis, Section 6.3.3; Resolving initial overclosures and specifying initial clearances for general contact, Section 29.3.5; and Adjusting initial surface positions and specifying initial clearances in ABAQUS/Explicit contact pairs, Section 29.4.5).

The status file

The status file (job-name.sta) is a text file that contains information about the progress of an analysis.

The ABAQUS/Standard status file

The ABAQUS/Standard status file contains a single 80-character record for each increment and is updated upon completion of each increment of an analysis. This record is written directly to secondary storage immediately at the completion of the increment. Therefore, the status file can be examined as the analysis job is executing, thus providing a monitor of the progress of the analysis. Other than specifying that a degree-of-freedom variable be monitored in the status file (as described below), the information written to the ABAQUS/Standard status file cannot be controlled.

The ABAQUS/Explicit status file

In ABAQUS/Explicit the status file (job-name.sta) contains, by default, mass and inertial properties for the model, initial stable time increment information, a synopsis of the progress of the analysis including total accumulated CPU usage and the current time increment size, and an estimate of the memory required to process each step. You can control additional output including the total kinetic energy, the energy balance, the identifier of the element with the smallest stable time increment, and the percent change in total mass of the model due to mass scaling.

The frequency at which summary increments are written to the ABAQUS/Explicit status file depends on the duration of the analysis in CPU minutes and the amount of output specified in the analysis. The following list provides general guidelines for when a summary increment will be written to the status file.

Summary information will generally be written:

  • Each time restart information, field output to the output database, or results file output is written.

  • Once per increment if the problem requires fewer than 20 increments.

  • 20 times during the step for a short analysis (less than 40 CPU minutes).

  • Every 2 CPU minutes for an analysis between 40 CPU minutes and 4000 CPU minutes.

  • Up to 2000 times during the step for a long analysis (over 4000 CPU minutes).

A degree-of-freedom variable can be monitored in the status file while the analysis is running. You can also write additional diagnostic information to the status file (see Explicit dynamic analysis, Section 6.3.3; Resolving initial overclosures and specifying initial clearances for general contact, Section 29.3.5; and Adjusting initial surface positions and specifying initial clearances in ABAQUS/Explicit contact pairs, Section 29.4.5, for details).

Errors that can be detected only while packaging the data for ABAQUS/Explicit or during analysis are also written to the status file.

Input File Usage:           
*PRINT

The *PRINT option can appear only once within a step definition.

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print


Requesting kinetic energy output

By default, the kinetic energy for the model is written to the status file. This output is written periodically throughout the step. You can choose to include or exclude the kinetic energy output for each step.

Input File Usage:           
*PRINT, ALLKE=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Allke


Requesting total energy output

You can write the energy balance for the model to the status file for each step. This output is written periodically throughout the step. By default, the energy balance is not printed.

Input File Usage:           
*PRINT, ETOTAL=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Etotal


Requesting output of the critical element

By default, the number of the element with the current minimum stable time increment and its value are output to the status file. This output is written periodically throughout the step. You can choose to include or exclude the critical element output for each step.

Input File Usage:           
*PRINT, CRITICAL ELEMENT=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Crit. Elem.


Requesting output of the change in the total mass

You can write the percent change in total mass of the model due to mass scaling to the status file for each step. This output is written periodically throughout the step. The percent change in total mass is printed by default only if mass scaling is present in the model.

Input File Usage:           
*PRINT, DMASS=YES or NO

ABAQUS/CAE Usage: 

Step module: OutputDiagnostic Print: toggle on Dmass


Monitoring a degree of freedom in the status file

You can write the current value of a specified point and degree of freedom to the status file. The value of the point and degree of freedom being monitored will appear in the status file for every increment written during the analysis.

When a degree of freedom is monitored in the ABAQUS/Standard status file, the same information is written to the message file (see above), but the specified frequency has no effect on the output to the status file.

Degree of freedom monitoring does not apply to eigenvalue buckling prediction, eigenfrequency extraction, or response spectrum procedures. For other linear perturbation procedures output for the monitored degree of freedom is the base state value.

Input File Usage:           
*MONITOR, NODE=node_number, DOF=dof

The node and degree of freedom being monitored can be changed from step to step by repeating the *MONITOR option. The node and degree of freedom specified in the last occurrence of this option in a step will be used for that step.

ABAQUS/CAE Usage: 

Step module: OutputDOF Monitor: Monitor a degree of freedom throughout the analysis, click Edit to select the point, Degree of freedom: dof


In ABAQUS/CAE only one point and degree of freedom can be monitored for an analysis; you cannot change the monitor request from step to step.

Requesting output in multiple steps

In general, output requests apply to the step in which they are given and to all subsequent steps until they are respecified. However, output specifications for linear perturbation steps (available only in ABAQUS/Standard; see below and General and linear perturbation procedures, Section 6.1.2) are treated independently of output requests for general analysis steps and apply only to a continuous sequence of linear perturbation steps.

Database output, printed output, and results file output are independent output modes in ABAQUS; therefore, changing the specification for one form of output does not affect the other forms.

General analysis steps

The default output requests are used in the first general analysis step of an analysis unless you redefine them. For subsequent general analysis steps, the definition of each form of output from the previous general step is maintained unless you redefine it.

Linear perturbation steps

The default output requests are used in the first of any sequence of linear perturbation steps unless they are redefined in that step. If a subsequent linear perturbation step is defined without an intermediate general analysis step, the definition of each mode of output from the previous perturbation step is maintained unless you redefine it. If an intermediate general step is defined, the default output requests are again used in the linear perturbation step unless they are redefined in that step.

Element matrix output in ABAQUS/Standard

In ABAQUS/Standard you can write element stiffness matrices and, if available, mass matrices for each step to a file. For heat transfer elements the operator matrices are written if stiffness matrix output is requested.

Element matrix output is available only for elements without internal nodes (unless those nodes have no active degrees of freedom) and with no acoustic or internal degrees of freedom. Examples of elements for which element matrix output is prohibited include acoustic, pipe, elbow, frame, gap, and interface elements as well as axisymmetric elements with Fourier modes. Element matrix output is not available for elements with coupled fields such as coupled temperature-displacement elements and pore pressure elements. For incompatible mode and hybrid elements, stiffness matrix output is prohibited while mass matrix output is available. A substructure matrix output request is used to write a substructure's reduced stiffness matrix, mass matrix, and load case vectors to a file (see Defining substructures, Section 10.1.2).

Element matrix output cannot be requested in a mode-based dynamic analysis (response spectrum, steady-state dynamic, modal dynamic, or random response). However, it can be requested in the eigenfrequency extraction analysis that precedes the mode-based dynamic analysis to output the mass and stiffness matrices.

The element matrices are written without the effects of nodal conditions; therefore, boundary conditions, concentrated loads, and the effects of multi-point constraints are not included in this output. The degrees of freedom are always in the global directions, even if a local coordinate system (Transformed coordinate systems, Section 2.1.5) has been defined at nodes associated with the element.

You must select the element set for which output is requested. For models defined in terms of an assembly of part instances (Defining an assembly, Section 2.9.1), element numbers written with element matrix output are internal numbers generated by ABAQUS/Standard. A map between internal numbers and the original element numbers and part instance names is provided in the data file.

Writing the element matrices to the results file

By default, element matrix output records are written to the ABAQUS/Standard results file. The record formats for the results file are described in Results file output format, Section 5.1.2. The file can be written in binary or ASCII format based on the file format you specify (see “Controlling the format of the results file in ABAQUS/Standard” above).

Input File Usage:           
*ELEMENT MATRIX OUTPUT, ELSET=element_set, 
OUTPUT FILE=RESULTS FILE

ABAQUS/CAE Usage: Element matrix output is not supported in ABAQUS/CAE.

Writing the element matrices to a user-defined file

You can write the element matrices to a user-defined file. The file name should not include an extension; the extension .mtx will be added. (See Input syntax rules, Section 1.2.1, for the syntax of user-specified file names.)

The format of the output file is compatible with the linear user element (see User-defined elements, Section 26.15.1).

Input File Usage:           
*ELEMENT MATRIX OUTPUT, ELSET=elset, 
OUTPUT FILE=USER DEFINED, FILE NAME=output_file_name

ABAQUS/CAE Usage: Element matrix output is not supported in ABAQUS/CAE.

Writing the element matrices to the data file

You can write the element matrix records to the ABAQUS/Standard data file.

Input File Usage:           
*ELEMENT MATRIX OUTPUT, ELSET=elset, 
OUTPUT FILE=USER DEFINED

ABAQUS/CAE Usage: Element matrix output is not supported in ABAQUS/CAE.

Including distributed loads

You can choose to write the load vector from distributed loads on the elements. By default, the load vector is not written.

Input File Usage:           
*ELEMENT MATRIX OUTPUT, ELSET=elset, DLOAD=YES or NO

ABAQUS/CAE Usage: Element matrix output is not supported in ABAQUS/CAE.

Controlling the frequency of element matrix output

You can control the frequency at which element matrix output will be written by specifying an output frequency in increments. By default, the element matrices will be output every increment (equivalent to an output frequency of 1). Specify an output frequency of 0 to suppress output of the element matrices. Unless the output is suppressed, the matrices will always be written at the last increment of a step.

Input File Usage:           
*ELEMENT MATRIX OUTPUT, ELSET=elset, FREQUENCY=N

ABAQUS/CAE Usage: Element matrix output is not supported in ABAQUS/CAE.

Writing the stiffness or operator matrix

You can choose to output the stiffness matrix (or operator matrix in heat transfer elements). By default, the stiffness (operator) matrix is not output.

Input File Usage:           
*ELEMENT MATRIX OUTPUT, ELSET=elset, STIFFNESS=YES or NO

ABAQUS/CAE Usage: Element matrix output is not supported in ABAQUS/CAE.

Writing the mass matrix

You can choose to output the mass matrix. By default, element mass matrices are not output.

Input File Usage:           
*ELEMENT MATRIX OUTPUT, ELSET=elset, MASS=YES or NO

ABAQUS/CAE Usage: Element matrix output is not supported in ABAQUS/CAE.

User-defined output variables in ABAQUS/Standard

In ABAQUS/Standard output quantities can be defined as functions of any element integration point variable listed in ABAQUS/Standard output variable identifiers, Section 4.2.1, by using user subroutine UVARM. Then, output variable UVARMn can be requested for output to the data file, the results file, or the output database.

User-defined state variables in ABAQUS/Standard

In ABAQUS/Standard you can allocate solution-dependent state variables and define them in user subroutines defining material behavior, as well as user subroutines FRIC, UEL, and UINTER (see User subroutines: overview, Section 13.2.1). Output variable SDVn can be requested for output of these state variables to the data file, the results file, or the output database. For user-defined elements output variable SDVn cannot be requested for output to the output database.

Postprocessing with ABAQUS/CAE

ABAQUS/CAE provides interactive graphical postprocessing from the ABAQUS output database file in the Visualization module (also licensed separately as ABAQUS/Viewer). Capabilities include model and deformed shape plotting, contour plotting, vector plotting, XY plotting, and animation.

Recovering additional results output from restart data in ABAQUS/Standard

Data needed for restart in ABAQUS/Standard are contained in several files that are generated when you request that restart data be written for an analysis: the restart (.res), analysis database (.mdl and .stt), part (.prt), and output database (.odb) files. Restarting an analysis, Section 9.1.1, describes the writing of restart data in more detail.

In ABAQUS/Standard you can extract output from the restart data and write it to new data (.dat), results (.fil), and output database (.odb) files using a postprocessing analysis procedure. If the original analysis included user subroutines, the postprocessing analysis procedure requires the specification of the user subroutines. The data, results, and output database file output requests are defined as described in Output to the data and results files, Section 4.1.2, and Output to the output database, Section 4.1.3. The output requests should be defined exactly as they would be in an analysis, except that:

  1. The output frequency specification has no meaning and is, therefore, ignored (unless you are recovering additional output from a previous direct cyclic analysis). Instead, you specify each increment at which output is to be generated in the postprocessing procedure definition.

  2. No default output is provided to the output database. Furthermore, model information, such as boundary conditions, is not written to the output database.

  3. Element set energy information cannot be recovered since it is not written to the restart file.

  4. Output is not available for procedures that do not support restart; for example, linear perturbation procedures.

The element sets and node sets that are defined for the analysis can be used for defining output sets during the postprocessing procedure. Additional sets can also be defined for the postprocessing procedure. You specify the step number in the restart file from which output is required. You cannot obtain results at the beginning of a step (see below).

Input File Usage:           
*POST OUTPUT, STEP=step_number

When the *POST OUTPUT option is used, it must appear as the first option in the input file. No data lines from the analysis input file are required. This option can be repeated as often as necessary to obtain further output. Since *POST OUTPUT is a purely postprocessing procedure, analysis options must not appear in the input file.

ABAQUS/CAE Usage: Postprocessing of restart data is not supported in ABAQUS/CAE.

Recovering additional output from a direct cyclic analysis

If you use this postprocessing technique to recover additional output from a previous direct cyclic analysis (see Direct cyclic analysis, Section 6.2.6), you must specify the iteration number in the restart file from which output is required instead of the increment. If temperatures (or predefined field variables) are read from a results (.fil) file in the original direct cyclic analysis, the same temperatures (or predefined field variables) must be read into the postprocessing analysis. This specification is needed to recover thermal strains at each time increment in the original direct cyclic analysis since the results file is not stored in the restart analysis database.

Input File Usage:           
*POST OUTPUT, STEP=step_number, ITERATION=iteration_number

There are no data lines associated with this option if the ITERATION parameter is specified.

ABAQUS/CAE Usage: Postprocessing of restart data is not supported in ABAQUS/CAE.

Example

A job can be submitted using the following input file. The analysis for which restart data were written must be specified when you submit the job (using the oldjob parameter of the ABAQUS execution procedure). This example creates a new data (.dat) file containing tabular data. The first two tables will contain data from increments 5 and 10 of Step 1 and will give the reaction forces of the nodes in the set CLAMP, which was defined when the analysis was run. The next table will contain data from increment 3 of Step 2 and will give displacements from the new node set TIP that is defined in this postprocessing analysis.

*HEADING
*POST OUTPUT, STEP=1
 5, 10
*NODE PRINT, NSET=CLAMP
 RF,
*POST OUTPUT, STEP=2
 3,
*NSET, NSET=TIP
 1200, 1203, 1205
*NODE PRINT, NSET=TIP
 U,

The following example input file recovers additional output from a previous direct cyclic analysis and creates a new output database (.odb) file, which contains the stress and strain for the elements in the set ELIST from each increment in Iteration 5 of Step 1, followed by data from each increment in Iteration 10 of Step 1:

*HEADING
*POST OUTPUT, STEP=1, ITERATION=5
*OUTPUT, HISTORY
*ELEMENT OUTPUT, ELSET=ELIST
 S,E
*POST OUTPUT, STEP=1, ITERATION=10
*OUTPUT, HISTORY
*ELEMENT OUTPUT, ELSET=ELIST
 S,E