Input a time disprgenized varying function

[DynamicEng]

Hi everybody
I would be grateful if someone could tell how I should input a force funcrion that differs with time with no special function. The value of force at time points( t=1,1.2,1.4,1.6,...(seconds)) are known.
Another related question is that can we enter these forces from a file(foe example a note pad or excel file) the way we do in Siesmosignal program. I have an earthquake record that the values are known in every 0.02(s) time interval. The record lasts for 30 seconds and this is needs huge input. What shall I do?
Thanks for help

 

[GregLocock]

Are you using ADAMS/VIEW?

Have you done the relevant tutorial?

try

File -> Import -> DAC/RPC III

You will need to convert your file to rsp or rpc III

Alternatively create a spline using your data - that is only 1500 elements, not actually very much.

Then you need to use that to drive your model.

Do the tutorial.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[DynamicEng]

Dear Greg
Thank you so much for answering my question. yes. I am using view. Unfortunately I have found no related tutorial to what I want to do. do you know where I can find it? how can I change my file to rsp? and finally I know how to make a spline with my data. I do it and set units to forc-time. but when I want to use them as a force function in function-builder there is an error with this concept: your function is not a time run one.Also when I push plot botton in function builder(I can see the function but program can not accept this as a runtime function) time steps are changed. Do you know how I should solve this?
Again I appreciate your answer and apologize for asking too many question and my english. I am a beginer and english is not my native language.
Regards.

 

[GregLocock]

Have you done the latch tutorial in

C:\MSC.Software\MSC.ADAMS\2005r2\help\mergedProjects\view_hlp\examples\view_gs.pdf

If not then I suggest you do it.

So far as data formats look at

C:\MSC.Software\MSC.ADAMS\2005r2\help\mergedProjects\view_hlp\exchange\file_formats.htm

or the equivalent on your system

also for splines

C:\MSC.Software\MSC.ADAMS\2005r2\help\mergedProjects\view_hlp\examples\spline.pdf

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[DynamicEng]

Dear Greg
I have studied the latch and spline tutorial before. I have problem with spline tutorial. I can import a excel file as a spline and measure. And when I enter my chart as a measur I can even see the plot in postprocessing menu as a function of time. But the problem is that function builder does not accept from me, neither measur nor spline imported values, as a function of time. I choose custom for force type and go to function builder. then I choose 'all objects' from 'getting objects data' and then choose all,browse,and related spline respectively. But there is a error that says it is not a time function. The tutorial has done a kind of similar approach to make a nonlinear spring but it is too vague. It hasn,t explained how we should deal with this error. Applogize me for asking to many questions. I really need this.
Regards

 

[GregLocock]

I understand you need this, but if you can't get the tutorial to work I can't really help. You could try the MSC adams forums at

http://www.mscsoftware.com/

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[alex56]

I am interested in this topic too.I will let u know if I got.
bye