NUMERICAL PROBLEMS ENCOUNTERED DURING EQUATION ASSEMBLY Warning in SAP

[CorporalToe]

Hello, I am getting this warning on my model but I do not know why. This is the error I get using the standard solver.

Operation : RUNNING ANALYSIS
Load Case : Solving Linear Stiffness from Zero (unstressed) initial conditions
NUMERICAL PROBLEMS ENCOUNTERED DURING EQUATION ASSEMBLY:

*** Informational Message 1 ***
Date & Time : 3/13/2024 2:08:50 AM
Computer : TANAY-PC-WIN
Run Tag : 0
Run Serial : 1
Operation : RUNNING CASES IN SERIES
Load Case : N/A
TOTAL TIME FOR THIS ANALYSIS: 00:00:00

https://files.engineering.com/getfile.aspx?folder=5b2be877-15ef-4fc8-a396-d0d4ce4dcbb7&file=Test.zip

 

[271828]

The truss looks unstable, like it could just fall over in the Y direction, or the top chord member could rotate about the X axis. However, it runs on version 25. Perhaps the new version locks some DOFs to make it stable -- not sure.

I recommend deleting all of the member end releases and running it again.

Another option: Restrain all of those top chord nodes in the Y direction and run it again.

 

[JoshPlumSE]

I'd say that the member end releases look fine. But, you just need to add an out of plane support to the top chord of the truss... to keep it from flopping over.