Search found 888 matches

by huffte
15 Aug 2011, 19:39
Forum: 04-Unexpected behaviour/errors
Topic: Imaginary Eigenvalues
Replies: 3
Views: 2080

Imaginary Eigenvalues

<t>In creating a very simple model with 3 DOF and known natural periods, I kept getting "Imaginary Eigenvalue" results.<br/> <br/> I gave up for the day and when I opened the file the next morning, I ran without changing anything. The results were then fine and the periods were correct.<br/> <br/> S...
by huffte
15 Aug 2011, 04:41
Forum: 05-Future developments & requests
Topic: Time History Records
Replies: 2
Views: 1630

Re: Time History Records

<t>Yes. I believe your suggestion will work fine. I tried SeismoSpect. It will open my PEER files with no problem. I can then select all of the data which has been read, copy and paste it into a new text file which is readable by SeismoStruct.<br/> <br/> Thank you for the tip. It will save me a lot ...
by huffte
14 Aug 2011, 19:36
Forum: 05-Future developments & requests
Topic: Time History Records
Replies: 2
Views: 1630

Time History Records

<t>It would be of a great help if more flexibility were built into the program regarding the reading of time history inputs.<br/> <br/> Specifically, it would be great if one could specify a starting line of the text file, a time increment, and the number of acceleration values per line.<br/> <br/> ...
by huffte
12 Aug 2011, 03:25
Forum: 02-Getting started with the modelling
Topic: Dynamic Time History Analysis
Replies: 14
Views: 5482

Re: Dynamic Time History Analysis

<t>I do have the book by Priestley - a fantastic book by the way, one which I use often - but cannot run the example problems on the current version of Seismostruct.<br/> <br/> Perhaps my judgement of the HHT integration scheme as inferior to the Newmark scheme was premature. I was trying simple mod...
by huffte
09 Aug 2011, 03:25
Forum: 02-Getting started with the modelling
Topic: Dynamic Time History Analysis
Replies: 14
Views: 5482

Re: Dynamic Time History Analysis

<t>After some tweaking of parameters - I am relatively new to SeismoStruct - it would appear that the Newmark integration scheme works much better for models which incorporate non-linear links as the sole source of inelastic behavior (this is compared to the default integration scheme).<br/> <br/> M...
by huffte
26 Jul 2011, 16:13
Forum: 02-Getting started with the modelling
Topic: Dynamic Time History Analysis
Replies: 14
Views: 5482

Re: Dynamic Time History Analysis

<t>Thanks for the tips. I have actually switched from the "plst" link to a bi-linear link and the Permanent Load analysis runs in a snap. The time history results are incorrect however - displacements are much too small, and I'm starting to wonder if there are some conversion problems internal to Se...
by huffte
22 Jul 2011, 22:55
Forum: 02-Getting started with the modelling
Topic: Dynamic Time History Analysis
Replies: 14
Views: 5482

Re: Dynamic Time History Analysis

Thank you Stelios. The Eigenvalue Analysis worked fine - the periods were not what I expected (much too low) - but that is something I'll tweak once I get everyhting running fine. I'm still puzzled at the failure of a successful Permanent Load execution.
by huffte
22 Jul 2011, 15:56
Forum: 02-Getting started with the modelling
Topic: Dynamic Time History Analysis
Replies: 14
Views: 5482

Dynamic Time History Analysis

<t>I am trying to run a dynamic time history analysis on a bridge with isolators modelled using zero-length "plst" links. I defined the time history input at supported nodes and defined no permanent loads, letting SeismoStruct auto-convert masses to loads.<br/> <br/> When I try to run the model, i r...

Go to advanced search