The following message is displayed when analyzing the system:
E801-11: Fatal Error: no mass in the system
Or "NAN" appeared in AutoPIPE reports.
Open the model in AutoPIPE, select Tools> Model input listing> check on all sub reports, and press OK button. In a few moments AutoPIPE Viewer will display the report, use the Edit > Find feature to look for all occurrence of "NaN"
NaN stands for Not a Number and means that there is a problem in the database somewhere. As indicated in the above image, notice that NaN occurred in a specific Pipe Property for Pipe Unit Weight or some other weight.
One or more of the following should fix your model
1. Open the model in AutoPIPE.
2. Open the input grids to view the the pipe properties.
3. Scroll over to see the column marked "Insul Dens".
Note: if insulation thickness = 0.00, change to a small value for all PipeIDs so that Steps 3-5 can be completed and then reset all insulation thickness values back to 0.00
4. Change the Density value(s) for all PipeIDs in the model to a different value.
5. After completed, change all the values modified above back to their original values/settings.
6. Repeat steps 3-5 for each PIPEID.
Note: Steps 1-6 above essential reset the materials to be sure that AutoPIPE updated the internal database from library data on the computer.
7. Create a new model listing report with Tools> Model Input listing command. and search for NAN again.
8. a. If there is no occurrence, great the model has been repaired, continue using the application. b. If NaN still exist, continue to next option.
3. Scroll over to see the column marked "Clad Density".
Note: if cladding thickness = 0.00, change to a small value for all PipeIDs so that Steps 3-5 can be completed and then reset all cladding thickness values back to 0.00
3. Open PipeID dialog screen.
4. Press the Tab keyboard key to cycle through the dialog in a predetermined sequence.
Note: Each press of the TAB key highlights the value in the indicated field. Confirm no space are at the end of the value, sometimes best to re-enter some values to be sure.
5. When the "Pipe Material" field is highlighted, change the existing selection to a different material from the drop down listing. Continue to press the Tab key until OK is selected, and then press the Enter / Return key on the keyboard to acknowledge the changes and to also close the dialog screen (yes, you could use your mouse to select the OK button).
6. Repeat steps 3-5 for each PIPEID noted in the initial search for NaN above.
7. Go back to each PIPEID from steps 3-5, changing the new value back to the original value (yes, you can use the mouse to directly change the materials back to the original settings).
8. Create a new model listing report with Tools> Model Input listing command. and search for NAN again.
9. a. If there is no occurrence, great the model has been repaired, continue using the application. b. If NaN still exist, continue to next option.
Check the Beam properties, confirm that the Beam Section Properties, Modulus does NOT = 0.00 but has a proper value.
1. Another solution, create a new model with a different model name then use File> Insert Model> AutoPIPE model (*.DAT) command to import the original file into this new model. Again create a model input listing searching for NAN. If NaN still exist, continue to step #10, otherwise the model has now been repaired, use AutoPIPE to finish the analysis.
2. a. If there is no occurrence, great the model has been repaired, continue using the application. b. If NaN still exist, continue to next option.
AS A LAST RESORT!!!, if Option #3, steps 8 & 9 did not resolve your issue, open the original model in AutoPIPE, select File Save AS> AutoPIPE Batch (*.NTL), save the NTL file as a different name from the current (i.e TEST.DAT), after the model has been exported, select File> Open> AutoPIPE Batch (*.NTL), locate and open the model (i.e. TEST.DAT) saved above.
Step #10 WARNING: After the model has been imported, confirm the entire model to be correct. Check every tab on the Model Input Grids, All Static/Dynamic settings, all load cases added to the model (wind, earthquake, etc..), and most importantly check all settings to be correct under Tools> Model Options> each and every page (i.e. General, Edit, Results, etc..). All of the items above may have been re-set to the default settings.