eleload as a time dependent uniform load

k.manoj · Post by **k.manoj** » Fri Sep 26, 2008 2:20 am

Dear Silvia:

I want to apply a time dependent lateral load as a uniform load on a column.
I could do only if it is a point load acting on a node as follows:

set IMfile "Imload.txt" ; # load time history
set IMfact 1; # load scaling factor
set dt 0.005
set TimeSeries "Series -dt $dt -filePath $IMfile -factor $IMfact";
pattern Plain 301 $TimeSeries {
load 21 1.0 0.0 0.0
}

I tried it for a uniform load as:

set IMfile "Imload.txt" ; # load time history
set IMfact 0.001; # load scaling factor
set dt 0.005
set TimeSeries "Path -filePath $IMfile -dt $dt -factor $IMfact";
pattern Plain 301 $TimeSeries {
eleLoad -ele 111 112 113 116 117 118 -type -beamUniform -1;
}

However the lateral load is constant (-1 kN/mm) and response did not change although I change the "IMfact".
How can I apply eleload as a time dependent uniform load?

Thanks

silvia · Post by **silvia** » Fri Sep 26, 2008 5:22 am

what do you mean, a time-dependent, constant load?

k.manoj · Post by **k.manoj** » Sat Sep 27, 2008 1:35 am

Dear Silvia:

Thank you very much for your prompt reply.

It is not a constant load. Actually I want to simulate impact effects of a RC column. So, I just want to apply a force-time history (i.e., force vs. time relationship which is defined in a separate file) on some elements as element loads.

So how can I do this?

I would be grateful if you could help me!

silvia · Post by **silvia** » Sat Sep 27, 2008 6:24 am

is this a a static or transient analysis?

k.manoj · Post by **k.manoj** » Sat Sep 27, 2008 5:21 pm

Dear Silvia:

Thanks again for your prompt reply.

It is a transient analysis. Actually I want to use variable transient analysis to avoid convergency issues due to large deformations at the impact region.

Thanks a lot in advance.

k.manoj · Post by **k.manoj** » Tue Sep 30, 2008 7:14 am

Dear Silvia:

Is it possible in OpenSees?

Thank you in advance.

silvia · Post by **silvia** » Tue Sep 30, 2008 7:43 am

frank's working on it, there is some problem with the eleLoad and the nonlinearbeamcolumn elements.

mhscott · Post by **mhscott** » Wed Oct 01, 2008 7:50 am

The nonlinearBeamColumn is assuming a 1.0 load factor from all element loads. Frank is working to fix it so that variable load factors are used.

k.manoj · Post by **k.manoj** » Wed Oct 01, 2008 10:40 pm

I am very happy to hear that Frank is working on it and thanks a lot.

I hope it will be very useful for the application of pressure or wave loadings (with variable load factors) and I am waiting for that capability in OpenSees.

Thanks