read binary results file (FNO) with a program

[AstroJohnPE]

Hi,

The results of a Nastran analysis are written to a binary file (the .FNO file). Do any users have a program to read the binary results file (.FNO) that they would be willing to share with the group? It could be a simple program that just converts the file to a text format, or a more sophisticated program that converts selected parts of the results file and/or does manipulations on the data.

For example, imagine a transient response analysis with 100 time steps.  It is tedious to review all of the results manually. A program would more quickly allow these types of things to be done:

• find the highest stress at each time step.
• find all of the nodes or elements with stresses above some value for each time step
• sum the reaction force at the constraints at each time step.

Before I start work on such a program, I thought that I would ask first. (Also posting to the Nastran forum. Reply to either forum 🙂)

John

2025 Jan 2. This post has been updated to attach the latest, FNO Reader version 1.84

[John_Holtz]

Hi @gbrisbinUZ9NP 

Based on item 5 (the contour plot in Inventor also shows values of 0), I think this issue is related to the Nastran results or how they are presented, and are not related to what FNO Reader shows. If the following ideas do provide some insight or answer, please create a new post on the Inventor Nastran forum so that the issue and answer (whatever it is) can be found more easily.

Here are my thoughts:

1. The contact result is not related to choosing to output Force or Stress. (Force does not need to be checked to get the contact results.)
2. There can be many contact results shown in the contour plot drop-down, but some of those results cannot be shown. For example, "SSLH Contact Normal Force" can be selected, but the values are shown as zero. This occurs because the result is in the contact elements, not in the contact nodes. The contact elements do not "exist" in Inventor, and Inventor is not programmed to transfer that result on to the nodes.
3. The results that you should be looking at is "Contact Force Along __ Axis". If necessary, such as for a pin inside a hole, you will need to project the X, Y, Z components of the force to get the normal direction. (I would need to think about how to do this, but based on the coordinates of each node, probably a vector cross-product of a vector from the axis to each node and the axis of the pin would give the normal direction vector for each node, then a vector dot product of the normal direction and contact force would give the normal component of the contact force.)

John

[AstroJohnPE]

Hi everyone,

I have released a new version of FNO Reader. Version 1.76 is attached to this post. (I will also attach the current version to the original post so that it is easier to find in the future. This thread is getting long and hard to find the latest version!)

The changes in this version include the following:

1. Added a new workflow: NAS to CAD. The Nastran file can now be converted to a CAD file (in STL format). Capabilities include exporting specific idealizations, the deformed shape (with a user-specified scaling factor) and excluding elements with particular "Element Status" results (such as excluding elements from an Explicit Dynamics analysis that have been deleted by the analysis.)
2. Corrected a crash that occurred in FNO to Table if the locations spreadsheet had blank rows.
3. Other minor changes to the interface, some of which are detailed in the "Updates" section of the documentation.

John

[johnster100]

Hi,

I am trying to get Max Stress from each time step from a Frequency Response Analysis. When I use the FNO reader my results are not in a usuable format (see attached CSV). They are not in columns and rows.

What am I doing wrong?

thanks,

John

[John_Holtz]

Hi @johnster100 

Correct me if I am wrong, but I think you are saying that you can read the output file (results-HDR.csv) with your Excel, the data comes in and is separated in rows and columns (at least it does for me), but it is not the layout you were hoping for. Is this what you see when you open the file with Excel? (The circles cells are the data you want.)

The problem is you have chosen the wrong options in FNO Reader. You want to use the workflow "FNO to Table". See the example "Result From Limited Locations (Use FNO to Table)" on page 5 of the documentation. In your case, the "limited" location is all elements in the model, so you do not need to select the Nastran file and specify which elements you want to check for the maximum stress. That is, just do steps 1 through 6.a and 11 through 16. (Steps 6.b through 6.e are to specify which elements to use when you do not want to search all elements for the maximum. Steps 7 through 10 are not applicable because Frequency response analysis does not output the stress at the corners.)

Depending on the model size, it may take a small bit of time for FNO Reader to read 409 sets of results and find each maximum, but it should be faster than massaging the -HDR file to get the 2 bits of data you want from each set of a dozen rows.

John

[IBuIBu]

Hi, it seems I cannot open the .fno file from my computer using this app, but it works to open the same .fno file from another computers. 

 This is the retun error text from details: 

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.UnauthorizedAccessException: Access to the path 'C:\Users\Ionel.bulancea\Downloads\FNO Reader ver 1.76\mzwgse6fn.FNO' is denied.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share)
at System.IO.File.Open(String path, FileMode mode, FileAccess access, FileShare share)
at FNO_Reader.Form1.FNO_ReadHeader(String Filename, Int32 FileNum, Int64 pbOffset, ProgressBar& pbar, Boolean KeepUniqueheaders, Int32& pbTarget, Boolean& ReadSuccessful, Int32 RecordTypeToKeep)
at FNO_Reader.Form1.PageMoveTo(Int16 direction)
at FNO_Reader.Form1.btnNext_Click(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

************** Loaded Assemblies **************
mscorlib
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9261.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll
----------------------------------------
FNO Reader
Assembly Version: 1.76.0.0
Win32 Version: 1.76.0.0
CodeBase: file:///C:/Users/Ionel.bulancea/Downloads/FNO%20Reader%20ver%201.76/FNO%20Reader.exe
----------------------------------------
Microsoft.VisualBasic
Assembly Version: 10.0.0.0
Win32 Version: 14.8.9032.0 built by: NET481REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/Microsoft.VisualBasic/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
System.Windows.Forms
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9251.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9261.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9032.0 built by: NET481REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Configuration
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9032.0 built by: NET481REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Core
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9261.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Xml
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9032.0 built by: NET481REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
System.Runtime.Remoting
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9214.0 built by: NET481REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Remoting/v4.0_4.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
<system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

Recently I only tried to upgrade from .Net Framework to .Net core 8. Not sure if this messed up something in my computer, but I tested to open the .fno file from another computer with Inventor 2025 installed, and it worked. Anybody have any idea how to fix this issue?

[John_Holtz]

Hi @IBuIBu 

The folder "C:\Users\Ionel.bulancea\Downloads\FNO Reader ver 1.76" is a strange name. I think the real name is "C:\Users\Ionel.bulancea\Downloads\FNO Reader ver 1.76.zip" but Windows is hiding the names of the file extensions.

I suggest:

1. Move the FNO file to a different folder, and do not put the FNO file inside a zip file/folder.
2. Find the option in your File Explorer to show the file extensions. It looks like this on my computer (Win 10, a lot of fancy stuff turned off.) "View > Show/hide > File name extensions". When the file name extensions are shown, you will see the name of the "folder" is really ".zip". In other words, you placed the .fno file you are trying to open inside a zip file!

(edit: for some reason the image is not appearing in the forum. See the attached file.)

John

[IBuIBu]

Hi,

Thank you for your help, but this is not the case.

I have open the zip file already.

I tried to load the .fno file from multiple other locations .. and still the same error.

Is not that I don't have access to these folders .. 

 

[John_Holtz]

Thanks @IBuIBu . I do not think .NET Core 8 is related to the issue. I'm sure if you check the installed apps, you will see that .NET Framework is still installed.

Use Windows File Explorer to check the properties of the .FNO file. It the "Read-only" attribute checked? FNO Reader is opening the file in a binary format which allows reading and writing. If the file is marked as read-only, the open statement would not be able to write to the file and would give the error message you showed. (Files copied from other computers will sometimes be identified as "read only".)

If the problem is not "read-only", another question is whether Inventor is installed on the computer and still works.

John

[IBuIBu]

You're right, the file was read only.

It works now.

Thank you!

[johnster100]

thanks,
i'll give that a go!

cheesr,
John

[AstroJohnPE]

I have released a new version of FNO Reader. Version 1.84 is attached to this post (and I will attach it to the original post to make the latest version easier to find). 

The changes in this version include:

1. When using the workflow FNO to Table to extract results from specified nodes or elements, the strength of this workflow is using the data in the model to get the desired node or element numbers. For example, the nodes associated with a contact face or force are listed in the Nastran file. The weakness of this method has been looking in the Nastran file to determine which ID number is associated with the desired contact or force. A new window has been added that will list all the ID numbers associated with the contacts, forces, constraints, etc. This makes it much easier to get the desired ID numbers. (I will also use this feature just to get a list of the contacts in the model and search for the contacts that include "Part a to part b".)
2. Fixed a couple of crashes.
3. Other minor interface changes, as described in the "Updates" section of the documentation.

John