The following tables describe some of the extensions used and created by the various programs. The listings are not necessarily all inclusive. It covers the files that are used most often and are of some use or interest to you.
The file that contains the model is the .fem file. It is created in the selected folder, referred to here as the root folder name. Other files are created to store the results of the analysis, the input for the processor, and so on, in the design scenario folders. So, the file and folder structure looks like the following:
 root folder name |
The folder created by the user. This is where the model is placed. | ||||
|
Yoke and clevis.fem Yoke and clevis.step |
The FEA model (.FEM) and the source CAD model if appropriate (STEP file in this example) | ||||
| Yoke and clevis.ds_data |
A folder created by the software to hold each design scenario. The .ds_data is automatically appended. Everything from this folder onward is created automatically. Users should not create any files or folders underneath the .ds_data folder. Deleting a design scenario in the interface will automatically delete the appropriate folder and its contents. | ||||
| 1 |
Folder for design scenario number 1. | ||||
|
ds.asd ds.cid ds.ldd ds.hfo ds.l10 ds.lgs ds.to |
Files with the results for design scenario 1. All analysis files are named ds. (The path indicates the real model name.) | ||||
| ds.mod |
The .MOD folder for design scenario 1. This contains the processor input files for the complete FEA model (nodes, elements, loads, and so on). These are the files read by the solvers and by the Results environment. (FoxPro compatible) | ||||
|
elemcond.dbf elements.dbf group.ldx model.dbf nodecond.dbf nodes.dbf |
|||||
| ds_inquired_results |
Folder for design scenario 1's Save to Report results. (Text files with an extension of .out located in this folder are automatically placed in the report.) | ||||
| ds_opt |
Folder for design scenario 1's design optimization, containing all the files necessary for the input and optimization log files. | ||||
| ds_restart |
Folder for design scenario 1's restart files, containing all the MES restart files at the user-specified time steps. | ||||
| ds_rpt |
Folder for design scenario 1's report, containing all the files necessary to display the report. | ||||
| 2 |
Folder for design scenario number 2. | ||||
|
ds.asd ds.cid ds.do ds.l ds.ldd ds.log ds.nso |
Files with the results for design scenario 2. All analysis files are named ds. (The path indicates the real model name.) | ||||
| ds.mod |
The .MOD folder for design scenario 2. This contains the processor input files for the complete FEA model (nodes, elements, loads, and so on). These are the files read by the solvers and by the Results environment. (FoxPro compatible) | ||||
|
elemcond.dbf elements.dbf group.ldx model.dbf nodecond.dbf nodes.dbf |
|||||
| ds_inquired_results |
Folders for design scenario 2's Save to Report results, design optimization, restart, and HTML report, respectively. | ||||
| ds_opt |
|||||
| ds_restart |
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| ds_rpt |
|||||
| MasterRpt |
Folder for master report. |
Some files listed below are indicated as nodal or element based binary format. The Analysis Parameters dialog has options to output most of these files to a text file as well; set the option before performing the analysis. After the analysis, a nodal based binary format file can be translated to a text file by using Results Options
Other Tools Nodal Results Translator in the Results environment. An element based binary format file can be translated using the stand alone program MKASO (in the Autodesk Simulation installation folder).
For a compact table of results file from each processor, refer to the page File Extension Summary.
Listing of the Extensions by Program
Modeling
Generic Model
| Extension | Description |
|---|---|
| .ACH | An archive of the model (a compressed zip file). Archives are useful for saving storage space or transmitting the model to another user. Use the File: Archive menu to create and retrieve archives. |
| .APV | A binary file with the input for a PV/Designer mesh. (PV/Designer is a template for creating pressure vessels meshes based on simple dimensional input.) |
| .DMIT | This is a backup file from a model created prior to version 20. The Direct Memory Image Transfer file, or the Autodesk Simulation copy of the CAD solid model. (binary) |
| .fixcase_log | A text file with results of changing the case of the model (used for remote submission to other computers). A text file with results of changing the case of the model (used for remote submission to other computers). |
| .ESD | This is a backup file from a model created prior to version 20. The Superdraw version of the complete FEA model, created by any means. (binary) |
| .ESC | This is a backup file from a model created prior to version 20. The Autodesk Simulation version of the complete FEA model, created by any means. (Access compatible database) |
| .FEM | The complete FEA model geometry (including CAD geometry and hand-built meshes), sketches, loads, and most other input entered through Autodesk Simulation. (binary) |
| .LDD | A brief text summary file created by the decoder (Check Model). Contains the number of elements created and any FEA-related warnings and errors. This file may be displayed during decoding if problems with the input are detected. |
| DS_NDXMAP.LOG | Text file with the results of transferring results from one model to another model. |
| .MSW | Text file with the results of the last mesh study. |
| .SKETCH | This is a backup file from a model created prior to version 20. It is the .fem file that contains the sketches created in the FEA Editor. |
| .SLG | A text file with the results (log file) from the 2D Mesh Generation. |
| ds.mod\*.DBF | Processor input files for the complete FEA model (nodes, elements, loads, and so on). These are the files read by the processors and by the Results environment. (FoxPro compatible) |
| ds.mod\ GROUP.LDX | A text log file of the results of converting the lines of the model into nodes and elements created by the decoder (Check Model). This file may be displayed during decoding if any geometry warning messages occur. |
| ds.mod\ MODEL.DBF | A series of database files (FoxPro compatible) containing settings entered by the user (element types, material properties, and so on). |
Midplane Meshing
| Extension | Description |
|---|---|
| .ETS | An error file created by the Midplane mesher when unable to create the mesh (binary format, Superdraw 3 compatible). Use it to see where the error occurred by renaming the extension to .ESD, opening the file, and viewing the layer numbers. |
| .MPR | Parameters passed to the Midplane mesher (text file). |
| .MSH | Text log file of the results of midplane meshing, but only of the final part. Use the .XML file (Mesh: View Mesh Results) to view the meshing results of the complete assembly. |
|
.SEN .SPT |
Binary and text files of seed points (coordinates) where the midplane mesher needed to adjust the nodes. |
| GROUP???.CNN | The element connectivity file (text format). This is created only when a single part is meshed. ??? represents the part number. |
Surface Mesh Enhancement
| Extension | Description |
|---|---|
| .ERM | An error file created by the Mesh Enhancement when unable to enhance the mesh (binary format, Superdraw 3 compatible). Use it to see where the error occurred by renaming the extension to .ESD, opening the file, and viewing the layer numbers. |
| .MRN | The surface mesh as it existed prior to using Surface Mesh Enhancement (binary format, Superdraw 3 compatible). |
|
.MLG .MPR .MSH |
A variety of text log files created by the Surface Mesh Enhancement. These recap the results of the mesh enhancement. The .MSH file contains the text that scrolls in the Enhancement window during the operation. The .MLG file contains the user parameters passed to the Surface Mesh Enhancement and the final results (nodes, elements, and element size). The .MPR file contains only the final mesh size. |
Linear
Performing Static Stress with Linear Material Models Analysis
| Extension | Description |
|---|---|
| .CST | A text file that sets up multi-point constraints (MPCs) in the analysis. This file is used by the processor. |
| .DO | Displacement results (nodal based, binary format). |
| .L | Text file (summary file) with echo of the input data and some solution statistics. Also includes optional output chosen by the user. |
| .LOG | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .MTX | Text file of stiffness matrix, activated from the Analysis Parameters: Output screen. |
| .NSO | Nodal stress results (element based, binary format) |
| .RHS | Text file of the right-hand side matrix, activated from the Analysis Parameters: Output screen. |
| .RO | Reaction force calculator results (nodal based, binary format). |
| .S | Text file of the stress output. This is activated from the Analysis Parameters: Output screen. |
| .STO | Strain results (element based, binary format) |
Performing Natural Frequency (Modal) Analysis
| Extension | Description |
|---|---|
| .CST | A text file that sets up multi-point constraints (MPCs) in the analysis. This file is used by the processor. |
| .FRQ | Listing of the natural frequencies (text format). |
| .LGM | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .ML | Text file (summary file) with echo of the input data and some solution statistics. |
| .MO | Mode shape results (nodal based, binary format). |
| .MTX | Text file of stiffness matrix, activated from the Analysis Parameters: Output screen. |
|
.S7, .S8, .S9, .S12 .S7_be, .S8_be, .S9_be, .S12_be |
A series of restart files necessary when doing a dynamic restart analysis (modal superposition). The files with the _be tag are created on an operating system that uses big endian files, such as HP-UX. The files without the _be tag are created on an operating system that use little endian files, such as Windows and Linux. (binary format) |
Performing Natural Frequency (Modal) with Load Stiffening Analysis
| Extension | Description |
|---|---|
| .FR8 | Listing of the natural frequencies (text format). |
| .LG8 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .ML8 | Text file (summary file) with echo of the input data and some solution statistics. |
| .MO8 | Mode shape results (nodal based, binary format). |
|
.S7, .S8, .S9, .S12 .S7_be, .S8_be, .S9_be, .S12_be |
A series of restart files necessary when doing a dynamic restart analysis (modal superposition). The files with the _be tag are created on an operating system that uses big endian files, such as HP-UX. The files without the _be tag are created on an operating system that use little endian files, such as Windows and Linux. (binary format) |
Performing Response Spectrum Analysis
| Extension | Description |
|---|---|
| .AS3 | Text file of the stress results. Activated from the Analysis Parameters screen. |
| .DO3 | Displacement results (nodal based, binary format). |
| .L3 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LG3 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .NS3 | Stress results (element based, binary format). Activated from the Analysis Parameters: Output screen. |
Performing Random Vibration Analysis
| Extension | Description |
|---|---|
| .AS7 | Text file of the stress results. Activated from the Analysis Parameters screen. |
| .DO7 | Displacement results (nodal based, binary format). |
| .DOP | Calculated power spectrum density output (nodal based, binary format) |
| .FRP | Text file that correlates the load case in the .DOP file to a frequency. |
| .L7 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LG7 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .NS7 | Stress results (element based, binary format). |
Performing Frequency Response Analysis
| Extension | Description |
|---|---|
| .AS5 | Text file of the stress results. Activated from the Analysis Parameters screen. |
| .DO5 | Displacement results (nodal based, binary format). |
| .L5 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LG5 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .NS5 | Stress results (element based, binary format). |
Performing Transient Analysis (Modal Superposition)
| Extension | Description |
|---|---|
| .AS2 | Text file of the stress results. Activated from the Analysis Parameters: Output screen. |
| .DO2 | Displacement results (nodal based, binary format). |
| .L2 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LG2 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .NS2 | Stress results (element based, binary format). |
| .ST2 | Strain results (element based, binary format). |
Performing Transient Analysis (Direct Integration)
| Extension | Description |
|---|---|
| .AO4 | Acceleration results (nodal based, binary format) |
| .AS4 | Text file of the stress results. Activated from the Analysis Parameters: Output screen. |
| .CST | A text file that sets up multi-point constraints (MPCs) in the analysis. This file is used by the processor. |
| .DO4 | Displacement results (nodal based, binary format). |
| .L4 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LG4 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .NS4 | Stress results (element based, binary format). |
| .ST4 | Strain results (element based, binary format). |
Performing Critical Buckling Load Analysis
| Extension | Description |
|---|---|
| .BLM | Text file of the buckling load multipliers calculated. |
| .DO6 | Displacement results (nodal based, binary format). |
| .L6 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LG6 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
Performing Dynamic Design Analysis Method (DDAM) Analysis
| Extension | Description |
|---|---|
| .DAS | Text results of the stress output. Activated from the analysis Parameters: Output tab. |
| .DOD | Displacement results (nodal based, binary format). |
| .FRD | Text file with a table of frequency, effective modal mass, and participation factor. |
| .LD | Text file (summary file) with echo of the input data and some solution statistics. |
| .LGD | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .NSD | Nodal stress results (element based, binary file). |
Nonlinear
Performing Mechanical Event Simulation (MES), or
Static Stress with Nonlinear Materials Analysis, or
MES Riks Analysis
| Extension | Description |
|---|---|
| .ACD | Tracks the contact status during an analysis (binary format). |
| .ACR | Concrete cracking and crushing status (binary format). |
| .ADO | Displacement results (nodal based, binary format). |
| .AGC | A text file with surface to surface contact information describing what contacts what. This file is created only by running the application GCONTACT from a command prompt window and specifying the runtime options. |
| .AL | Text file (summary file) with echo of the input data and some solution statistics. |
| .ALG | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. This file is useful because it shows the convergence history. |
| .ARO | Reaction force output (nodal based, binary format). Activated from the Analysis Parameters: Output tab. |
| .ASO | Nodal stress results (element based, binary format) |
| .AST | Strain results (element based, binary format). |
| .ATO | Auxiliary output file with plasticity and damage results (element based, binary format). |
| .BNV | Restart files (binary format). |
|
.BSO .BSObin |
Beam stress output (text format and binary format, respectively). This option is activated from the Element Definition dialog for the beam-element part. |
|
.BST .BSTbin |
Beam strain output (text format and binary format, respectively). This option is activated from the Element Definition dialog for the beam-element part. |
|
.C22 .C23 |
Tracks the contact status during an analysis (binary format). |
| .EGC | A Superdraw compatible file showing which edges are used in surface to surface contact. This file is created only by running the application GCONTACT from a command prompt window and specifying the runtime options. |
| .EOR | A binary file with the rotation data for beam elements. |
| .LCM | Load curve multiplier file. This contains the load curve multiplier for each load curve at each time step (binary format). Since results-based loads are not input as a function of time, the processor outputs the load curve multiplier for the convenience of the Results environment to display the magnitude of the loads at each time step. |
| .LTM | A text file that contains the load case number for the Results environment, the actual number of iterations used by the processor to get to the load case number, and the analysis time at which the load step occurs. |
| .R00, .R8, .R9, .R25, .RNV | Restart files (binary format). |
| .RMP | Tracks the restart files available. |
| .SSC | A binary file with surface to surface contact information describing what contacts what. |
| ds_restart folder | A folder containing saved restart files, created when multiple restart data is saved. The folder contains the standard restart files (.BNV, .R00, .R8, and so on) appended with the step number. |
Natural Frequency (Modal) with Nonlinear Material Models
| Extension | Description |
|---|---|
| .AFR | Text file with the frequency results. |
| .AL1 | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .AML | Text file (summary file) with echo of the input data and some solution statistics. |
| .AMO | Mode shape results (nodal based, binary format). |
Thermal
Performing Steady-State Heat Transfer Analysis
| Extension | Description |
|---|---|
| .CST | A text file that sets up multi-point constraints (MPCs) in the analysis. This file is used by the processor. |
| .HFO | Heat flux results (element based, binary format) |
| .L10 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LGS | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .LRD | Text file with summary of body-to-body radiation results (faces involved in radiation and view factors). |
|
.SEM .SER |
Binary files related to the body-to-body view factor calculation. |
| .TO | Temperature results (nodal based, binary format). |
| .VWF | Binary file with body-to-body radiation view factor matrix. |
Performing Transient Heat Transfer Analysis
| Extension | Description |
|---|---|
| .CST | A text file that sets up multi-point constraints (MPCs) in the analysis. This file is used by the processor. |
| .L11 | Text file (summary file) with echo of the input data and some solution statistics. |
| .LGT | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .LRD | Text file with summary of body-to-body radiation results (faces involved in radiation and view factors). |
| .LTT | Text file with time step number and corresponding time. |
|
.SEM .SER |
Binary files related to the body-to-body view factor calculation. |
| .THF | Heat flux results (element based, binary format). |
| .TTO | Temperature results (nodal based, binary format). |
| .VWF | Binary file with body-to-body radiation view factor matrix. |
Electrostatic
Performing Electrostatic Analysis
| Extension | Description |
|---|---|
| .EFO | Field or current results (element based, binary format). (In the unlikely event that you access this binary file directly, be aware that the units of displacement field are current × time/length2.) |
| .EFR | Electrostatic reaction force results and charge from Field and Voltage analysis (nodal based, binary format). Activated from the Analysis Parameters: Options tab. (In the unlikely event that you access this binary file directly, be aware that the units of force are voltage × current × time/length.) |
| .EL | Text file (summary file) with echo of the input data and some solution statistics. |
| .LGE | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .NEO | Electrostatic flow-line results (element based, binary format). |
| .VO | Voltage results (nodal based, binary format). |
Mass Transfer
Performing Transient Mass Transfer Analysis
| Extension | Description |
|---|---|
| .LGU | Text file (statistics file) of the text that scrolls in the Analysis window during the analysis. |
| .UFL | Text file (summary file) with echo of the input data and some solution statistics. |
| .UME | Mass flux and mass rate results (element based, binary format) |
| .UMN | Species concentration results (nodal based, binary format) |
Other
Performing Design Optimization and Design Studies
| Extension | Description |
|---|---|
| _dsN_OPT.FEM | The FEA model of the optimized design, created automatically by the Design Optimization analysis. The original model name is appended with _dsN, to signify which design scenario number N the optimized design is for, and _OPT to signify the model is an optimization result. |
| ds_opt folder | A folder, located in the modelname.ds_data\design scenario folder, containing the input and text file results for the design optimization. The following files are located in the ds_opt folder: |
| .OPT1 | Text file with the input for the design optimization analysis. |
| .OPT1DSLOG | Text file of the design study log: the text that scrolls in the Design Study Analysis window during the analysis. |
| .OPT1OPTLOG | Text file of the design optimization log: the text that scrolls in the Design Optimization window during the analysis. |
| .OPT11 | Text file with the results from the design study analysis. This data is used to display the sensitivity graphs in the Design Optimization dialog. |
| .OPT12 | Text file with the optimization history from the design optimization analysis. This data is used to display the history graphs in the Design Optimization dialog. |
Performing Weight and Center of Gravity
| Extension | Description |
|---|---|
| .LG9 | Text file (statistics file) with echo if input during the solution. |
| .NCG | A binary file with the mass density of the part and volume of each element. |
| .WCG | Text file (summary file) with echo of the input data solution results. |
Fracture Analysis
| Extension | Description |
|---|---|
| .CRACKn | A binary file with the results for crack number n. |
| .FRACTURE | A binary file with the results for all cracks in the model. This is a combination of the individual .CRACKn files. |
| .LOGFRAC | Text log file from the fracture analysis processor. Any errors or warnings during the analysis will be in this file. Successful analyses also include results. |
Miscellaneous Files
| Extension | Description |
|---|---|
| .APIF |
Autodesk Simulation Part Information File, which are all the attributes of a part saved to an independent file. This information can be read into a different part or different model. See the paragraph Miscellaneous Functions (Hide, Deactivate, Copy and Paste) on the page Setting Up and Performing the Analysis: Using the FEA Editor Environment for details. |
| .CLC | A text file used with the Load Combination Utility. It lists the models, load cases, and multipliers to use when combining the results of multiple models. |
| .CLG | Text log file from the Load Combination Utility. |
| .LCF | Text log file from the curve-fitting routine (used for nonlinear hyperelastic and foam material models). |
|
.~SD .~SH |
Files used for meshing. |
| .CID | Coordinate system ID mapping (binary format). |
| .ERO | Text file with output from program MKASO (translates element based binary results to text). |
| .PDX | A processor pause/stop file. When you click the Pause or Stop button during an analysis, this file is created to communicate with the processor. This file is normally deleted, but if the processor is killed before it detects the .PDX file, the .PDX file will still exist. This is a problem only if you then start an analysis from outside of the user interface, such as with a batch file or running from a command prompt. In this case, the processor encounters the .PDX file and stops. Delete the file to get the analysis to run. |
| .T* | Temporary files from the processors, normally deleted after a successful exit from the processor. |
| .TM$ | File used for meshing. |
| .TOP | Text file with options passed to the processor. |
|
.TSH .TSX .TSY |
Miscellaneous meshing files (binary format). |
| .TT$ | File used for meshing. |
| .VSS | Text output from the sparse solver. Created by most processors that use the sparse solver. |