Seismosoft | Earthquake Engineering Solutions

Hi
I am trying to use more than one (Time-History curve) in my Dynamic analysis problem.
Therefore, I need to write a new starting time on the (Analysis Start Time) to begin a new (Time-History Stage).

The problem is that the (Analysis Start Time)box can not be activated on the (Time-History curve).
How to activate it ??? Please, any one can help?
Thank you

Dear Mohamed,

1) if you wish to apply more than one record to the same nodes, you need to join those records in one single time-history file, or create two coincident nodes to which the different records can be applied to (see http://www.seismosoft.com/forum/topic.asp?TOPIC_ID=367)

2) if you wish to change the 'start-time' to be considered for a record, you need to change that parameter when loading the time-history.

Seismosoft Support

Dear Seismosoft Support

Thank you for your e-mail. My record is a 50 seconds long Ground acceleration with 0.005 time step (that is 10000 steps). So Seismo will take it in 2 records.

So, I need to apply the two-nodes choice with rigid link. This requires a 0 start time for the 1st record and a 25 start time for the 2ed record.

The problem is that the Start Time box is always not activated even when I first load the record.

Thank you

Yes, you are right, apologies for the imprecision in our previous response; you need to enter a 'Delay' of 25 seconds in your second record.

Seismosoft Support

Hi

I am using the 'Delay' command for the 2ed curve but
I still get the error message(end of time-history stages should
be within the curve range).
I use (0 to 25 sec) stage for each curve. I also tried
both ranges(0 to 25) and (25 to 50). I also tried
the full range (0 to 50). Please, help.

Thank you

Dear benamer,

We cannot quite understand what might be going wrong. If you send us your model files, we may look into it.

Seismosoft Support

Dear benamer,

We apologise for the very long delay with which we are providing feedback on this matter.

The program was indeed not behaving in the way we had described or suggested; our mistake.

In the upcoming version of SeismoStruct, the maximum number of data points that can be used in the definition of time-history curves will be 150.000, so that users will no longer need introduce workarounds such as those that you were trying to implement.

Nonetheless, and in order to avoid unnecessary long analyses, we still very much advise users to consider cropping/truncating very long input accelerograms (if they contain large portions of negligible motion at their start and end), or use SeismoSignal to increase the time-step used to define the record (if its value is unnecessarily small). The following post, although referring to SeismoMatch, discusses this matter in some further detail: http://www.seismosoft.com/forum/topic.asp?TOPIC_ID=611 .

Seismosoft Support