How to apply load as a time series?

[Lanka]

Hi Silvia,
I want to apply load as time series at a particular node. But, I am having problem in defining load pattern . Here is the part of my code where I define load pattern;

set LoadSeries1 "Series -dt 0.00024414 -filePath ./commandForce.txt -factor 1.0"

pattern Plain 1 $LoadSeries1
{

load 382 1 0

}

The time step between load values is 0.00024414 sec where the values are taken from a file specified by commandForec.txt.

The above load time history is applied at node 382 in direction 1.

Could you plese help me on this?

Thanks.
-Lanka.

[silvia]

have you looked at the examples manual?
i do that for the uniform eq.

[Lanka]

Yes, I did.
When we use uniformeq. command we don't specify node information because the command acceleration is applied to all fixed nodes in a particular direction. But load pattern command needs node details.

This is the error message I am getting when I specify node details.

"error reading load pattern information in { } invalid command name "Series"

Could you clarify me on this issue?

Thanks.

[silvia]

then look at the multiple-support excitation example

[Lanka]

Thanks!
I looked at the examples. I am little bit confused.
In all the examples dynamic lateral load is specified as either acceleration (using uniform eq.) or displacement (using multiple support eq.). Its seems some of the commands are unique to the Multiple support excitation or uniform eq.
Can't we apply dynamic lateral load as force time series (units in N) using pattern plain command?

[silvia]

sure, you can apply nodal forces or displacements -- these are on the lhs of the equilibrium equation. the uniform excitation deals with the rhs of the equilibrium equation and the inertial forces are calculated "automatically".

[Lanka]

Thanks!
Do we have any example shows a dynamic lateral load analysis by applying a force time series? I looked at the example manual all of them are using either uniform eq or multi-support eq.

[silvia]

nope, but it's a combination of the load applied in the static pushover analysis and the analysis part of the eq analysis.

[k.manoj]

You should specify all the dof of the node on which you apply lateral load. So the correct script may be:

set LoadSeries1 "Series -dt 0.00024414 -filePath ./commandForce.txt - factor 1.0"

pattern Plain 1 $LoadSeries1
{

load 382 1 0 0

}