Hi,

I have a question about the dynamic analysis output processor of CaesarII.

I am running an analysis for a slug flow system in time history.

The problem is the dynamic output processor. My questions are:

1. Where can I find more information on dynamic analysis with CaesarII in time history mode. The information on dynamic analysis (time history) in the application guide is very poor.

(the answer to the first question cold solve all of my other problems but ...)

2. What exactly are the 'max resp' calc and the '1000 msec' calc? In my opinion these are 'the maximum response of the system to the force' and 'the response of the system after 1000 mseconds.

3. When you view the restraints for the 'max resp' and the '1000 msec' case, a print out of the loadings on all restraints is printed on screen. Are these forces a combination of the dynamic and static forces in the system or are these forces only dynamic and to be added on top of the static restraint values?

Regards,


Timo Stek

Information Sources:
Use the index in the Quick Reference Guide, since this is a combined index for all three manuals. There is information on this subject in all three, so the Quick Reference Guide will save you a lot of time.

Refer to our June 1994 newsletter for an article on a time history example. Here is a direct link: http://www.coade.com/newsletters/jun94.pdf

Max Response and 1000 msec Response
Obviously, there is a lot of output possible from a time history run, so much so you really don't want to see it. So back in the dynamic input, you specify how many reports (or snapshots of the results you want to see. So if your analysis is for 1000 msec, and you request 2 reports, you get one at 500 msec, and another at 1000 msec.

This is great in that it cuts down on the amount of output to wade through, but ... how do you know you're looking at the worst or most critical case (time step)? Well you don't, and chances are you're not looking at the worst or most critical case (time step). So, we track the maximum response for everything, and generate an additional report, labeled Maximum Response. This report shows for each item, what the maximum response was and when it occured.

For example, in the displacement report, node 10 may have a maximum X displacement of 0.75" at 840 msec, while it may have a maximum Y displacement of 0.6" at 730 msec. Note these maxima occur at different times. Note also that neither value would appear in the 500 msec or 1000 msec reports.

Dynamic or Dynamic + Static?
That depends on which report you're looking at. Assuming you setup combination cases in the input, then your available reports at the output level are:
1) Dynamic Case #1
2) Combination Case #1

The dynamic case is just the dynamic event. The combination case is the dynamic response added to whatever else you requested in the input (usually just the static response).

[ August 13, 2001: Message edited by: rich_ay ]