Search found 888 matches

by huffte
01 Sep 2020, 00:41
Forum: 04-Unexpected behaviour/errors
Topic: IDA not yielding results
Replies: 4
Views: 326

Re: IDA not yielding results

Just to be clear and rule out the potential units issue: 1. When you define the time history curve, you specify a factor of 0.01 to get cm to m. 2. When you define the loading, you specify a factor of 1.0, since you converted the units in defining the curve. If these are true, I believe you are corr...
by huffte
31 Aug 2020, 16:02
Forum: 02-Getting started with the modelling
Topic: eigen value
Replies: 4
Views: 258

Re: eigen value

You can place a node in the exact center and connect it to the corners with rigid links. Depending on your intended model, you may have to use rigid links to more than the corners.
by huffte
31 Aug 2020, 15:05
Forum: 02-Getting started with the modelling
Topic: eigen value
Replies: 4
Views: 258

Re: eigen value

If the exact center of mass has, indeed, not been defined, then you likely have eccentric mass distributions at one or more levels, which would indeed produce multi-directional displacements, even if the stiffness is symmetric. Both mass and stiffness must be perfectly symmetric in order to expect n...
by huffte
31 Aug 2020, 15:02
Forum: 04-Unexpected behaviour/errors
Topic: IDA not yielding results
Replies: 4
Views: 326

Re: IDA not yielding results

This looks as though it could be a units problem. I typically load accelerograms in units of g. I typically use units of inches and seconds. So, when I apply a particular accelerogram as a nodal loading, I have to specify a factor of 386. Just a thought, but double-check the scale factor you applied...
by huffte
16 Aug 2020, 01:03
Forum: 03-Analytical/modelling capabilities
Topic: Regarding target displacement
Replies: 14
Views: 709

Re: Regarding target displacement

The Help system has a lot of good information on 'Target Displacement'. I typically don't use auto-calculated target displacement, but specify my own. Start with a reasonable guess. If that doesn't push it far enough, increase on the next run. If that pushes too far, you can reduce on the next run. ...
by huffte
11 Aug 2020, 14:44
Forum: 02-Analytical capabilities
Topic: Maximum Direction Ground Motion
Replies: 5
Views: 688

Re: Maximum Direction Ground Motion

You should be able to manually generate your CMS, save to a text file, and define the target from the file, rather than auto-generating a response spectrum.
by huffte
25 Jul 2020, 16:15
Forum: 03-Analytical/modelling capabilities
Topic: Regarding target displacement
Replies: 14
Views: 709

Re: Regarding target displacement

Ss and S1 are typically read from maps or obtained from online tools. The best option is the ATC app. USGS also has an app which can be used but the values are geomean while asce used RotD100. You can use ATC app values directly or adjust usgs values. https://hazards.atcouncil.org/ These are for US ...
by huffte
10 Jul 2020, 14:29
Forum: 03-Unexpected behaviour/errors
Topic: Range check error
Replies: 7
Views: 1965

Re: Range check error

I would like to add that this is not unusual. One of the developers of spectral matching techniques has stated that they discard approximately 80% of the records they generate through spectral matching. As noted by the Seismosoft team, it is important to have a reasonably close match to shape and am...
by huffte
05 Jul 2020, 19:34
Forum: 03-Analytical/modelling capabilities
Topic: Period of equivalent single degree of freedom system
Replies: 2
Views: 197

Re: Period of equivalent single degree of freedom system

Hi Koloubos. I assume you are referring to an 'equivalent sdof' used in direct displacement based design and analysis. I don't think you will find that, as there are multiple means of making that determination in the literature, while SeismoStruct is a full model with no need to reduce to an equival...
by huffte
27 May 2020, 00:11
Forum: 02-Analytical capabilities
Topic: Scaling factor significant figures
Replies: 4
Views: 369

Re: Scaling factor significant figures

Many Japanese records are very large, with 60,000 or more data pairs. One option is to specify a frequency of 2 and double the specified time step to read only every other value instead of every value, essentially cutting the record size in half. I have used this before several times. It will be imp...

Go to advanced search