Using discrete/analyically rigid elements with buckling analysis
Using discrete/analyically rigid elements with buckling analysis
(OP)
So I'm trying to model a column with 4 rigid links for a buckling analysis. The overall structure is simply supported and there is also a linear spring at the middle joint. Each of the rigid links are connected to the one below via a rotational spring. I attached the model for reference.
However, when I try to run it, this error pops up: DIFFERENTIAL STIFFNESS MATRIX IS COMPLETELY NULL. THE EIGENPROBLEM CANNOT BE SOLVED. IN A *BUCKLE ANALYSIS THE MOST LIKELY CAUSE IS THAT A NONZERO LOADING PATTERN WAS NOT SPECIFIED VIA *BOUNDARY, *CLOAD, *DLOAD, ETC,.
What does this error mean/how can I fix it? Thanks!
BTW, this model is with analytical rigid parts for the links but the same error occurs with the discrete rigid parts too.
However, when I try to run it, this error pops up: DIFFERENTIAL STIFFNESS MATRIX IS COMPLETELY NULL. THE EIGENPROBLEM CANNOT BE SOLVED. IN A *BUCKLE ANALYSIS THE MOST LIKELY CAUSE IS THAT A NONZERO LOADING PATTERN WAS NOT SPECIFIED VIA *BOUNDARY, *CLOAD, *DLOAD, ETC,.
What does this error mean/how can I fix it? Thanks!
BTW, this model is with analytical rigid parts for the links but the same error occurs with the discrete rigid parts too.





RE: Using discrete/analyically rigid elements with buckling analysis
Tara
http://tinyurl.com/4ydjg7m
RE: Using discrete/analyically rigid elements with buckling analysis
Thanks for the response but yes I specified a unit vertical load on the top link.
RE: Using discrete/analyically rigid elements with buckling analysis
Tara
http://tinyurl.com/4ydjg7m
RE: Using discrete/analyically rigid elements with buckling analysis
RE: Using discrete/analyically rigid elements with buckling analysis
RE: Using discrete/analyically rigid elements with buckling analysis
Tara
http://tinyurl.com/4ydjg7m
RE: Using discrete/analyically rigid elements with buckling analysis
But I think you're on to something with the stiffness ratio idea. Thanks for the help!