The steel design checking according to AISC 360-10 reverse the sign of the axial load making compression as tension in the design stage leading to consider all columns (compression members) as tension members and vs. versa. Be aware of the this guys, and this is not acceptable from Bentley/STAAD to release updated version without checking for such big mistakes.
A new version of STAAD that contains the correction for these errors is currently undergoing testing. We are hopeful that it will be ready within the next 1-2 weeks.
Shame on you Bentley STAAD team, it seems you are dealing with the matter just like an ostrich, don't you think you should post a note in the STAAD news screen alerting user about the issue, how about those trust STAAD blindly and consider the wrong results, who will be responsible for catastrophic failures? it is over than two months when i informed you about the problem and you guys keep it secret between us, this is not the ethic of doing business neither a good scientific behavior.
Bentley should start putting DISCLAIMER as well same what other programs have. This design bug is not happening only to staad. I remember four years back that I experienced the same thing with the other program. We as structural engineers should not trust any program without the clear understanding how to use it or without doing any verification of it. Using the software blindly is not acceptable for engineering professionals. In our office, before we use the latest releases we test them first on simple structures and we make sure that the results is almost parallel with our other programs.
Hey x_structures, you don't notice what they did??? They are complaining already what they found out, so don't put your head here to say that you are better than this guys. If you did so then you must be the first to complaint here. One thing you should keep in mind is that the cost of the software. Are you silly to buy a software as cost as your life instead of programming in excel with a minimal cost???
We just want that this programmer/developer will undergo testing of their product prior releasing such version.
We have been working extremely hard to post a new build but as I am sure you appreciate cannot simply post it without re-running a full qa test programme which includes a vast number of regression tests along with new tests and tests on the issues identified here. I was expecting that this could have been completed sooner, but it has taken longer than expected. We are pushing very hard to get this complete and posted early next week and will post notifications here and on the STAAD.Pro news website informing everyone when it has completed all the testing and is formally released.
Please note the patch release has been posted and available for download. This includes fixes for the issues discussed in this thread regarding AISC 360-10 and also addresses a number of other issues that are described in more detail in the Revision History and this blog:- http://communities.bentley.com/products/structural/structural_analysis___design/b/analysis_and_design_blog/archive/2012/12/05/staad-pro-v8i-selectseries-4-patch-release.aspx
I've just posted a PDF file containing verfication problems for STAAD.Pro V8i (SELECTseries 4) build 20.07.09.20 take from several design examples found in the AISC Design Examples. These are some common examples, including a non-slender, double-angle member in compressoin as previously discussed in this thread. This file can be found by selecting the Files tab above or by direcly by visiting this page:
[Edit 2012-12-18 - I'm currently making some further edits to this document based on responses. Thank you for your patience.]
Note: You can download a copy of AISC Design Examples for free from the AISC web site: http://www.aisc.org/content.aspx?id=24314
Jason Coleman, PE
Bentley Systems Senior Manager Technical Content
Jason, thanks for the examples. I took a look at Example 6 and I still don't see how you are accounting for intermediate connectors. It's even mentioned in the example but then never addressed that I could see. I agree with the bottom line, just don't think it is clear that it requires at least 2 intermediate fasteners so that y-y axis buckling doesn't control.
I also found some typos. I've attached the corrections. You'll get my bill. :-)
Sorry, guess it wasn't clear that that was a question. How are you accounting for intermediate connectors?
As of now STAAD does not calculate connector spacing or take that as an input from the user through a design parameter. It simply assumes that the built up section, consisting of two or more shapes, are adequately connected at intermediate locations such that effective slenderness of individual components does not exceed ¾ x governing slenderness of the built up section.