displacement ver. force-based pushover

[yalham]

Dear all

In order to define lateral pattern in pushover analysis, two different approaches may be used;

1- "Force based" for which lateral pattern is essentially force values at DOFs.
2- "displacement based" that define displacement values in DOFs.

Would you please check the following statements for this two types of pushover analysis?
And if anyone has experience on performing "displacement-based" pushover, would he/she please notify me.

A- For a "Force based" analysis I think we have to perform a "displacement-controlled analysis". So we use "load" command in conjunction with displacement controlled integrator in Opensees.

B- However, in order to perform a "displacement-based" analysis we shall use "SP" command and also force controlled integrator in Opensees, (a force-controlled analysis for displacement-based type of pushover).

Are these two expressions ok? (A & B)

sorry for a long post.
thanks in advance

[vesna]

Yes, they are valid, although the second one is not very common way of doing pushover analysis.

[Tas]

Hi,
There is an interesting article about the "displacement-based" push over, on http://www.lessloss.org/main/index.php? ... ew&gid=128

[yalham]

Thank you all for notes and the article

And in displacement-based pushover, do we use "sp" in order to apply displacement values? And also do we use load-control integrator?

[vesna]

Yes, you are right. One more thing is important to note. When using "sp" to enforce nodal displacement one needs to use Penalty constraint handler.

[yalham]

thanks for the reply and your instruction. have a very good time