Quasi-static analysis

[SPR Baker]

Dear all
What is quasi-static analysis?
Do some software such Etabs, Robot Structural Analysis have it or not?
Thank you

 

[r13]

Do you have an example that is tied to "quasi-static"? Please provide.

 

[BAretired]

https://imechanica.org/files/l5-quasi-static.pdf

BA

 

[JoshPlumSE]

I believe all this is referring to is using the slow application of load in a dynamic analysis in order to get essentially static results. My guess is there is something about the non-linear contact elements that make the solution from a "dynamic analysis" more likely to converge than when doing an true static analysis.

For what it's worth, I have used "quasi-static" analyses when I wanted to verify that our dynamic analysis is working correctly. That means I applied the load slowly, and compared it to the static analysis results that I got. Granted, my situation was a lot easier than what they're talking about in the document, because mine was merely a linear analysis.

 

[IDS]

This is how the Strand7 program describes its quasi-static solver:

"The Quasi Static solver has attributes of both the Nonlinear Static solver and the Nonlinear Transient Dynamic solver. Like the Nonlinear Static solver the Quasi Static solver calculates the nonlinear static equilibrium of the system, considering nonlinear behaviour due to geometric, material and contact nonlinearity, whilst dynamic inertia effects are ignored. Unlike the Nonlinear static solver, the Quasi Static solver does not use increments to define the load history; instead it uses Factor vs Time tables assigned to the selected load cases, just like the Nonlinear Transient Dynamic solver.

In addition, the Quasi Static solver considers nonlinearity due to material creep (a time-dependent nonlinearity, which can also be considered by the Nonlinear Transient Dynamic solver)."

That seems to agree with what Josh said.

I don't know whether Etabs or Robot Structural Analysis have it.


Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[oldestguy]

Also do Google search. Plenty of scoop there.