Hi,
I was interested to know if there were any member types that could be used within Robot to define lateral bracing members in such a way as to prevent them from attracting any gravity loading and only allow them to attract wind loading? I am designing a steel structre which is stabilised laterally by tension only cross bracing.
Thank you in advance for your help.
Graham
Solved! Go to Solution.
Solved by Artur.Kosakowski. Go to Solution.
Try to define them as tension only elements (and exclude them from self-weight load list).
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Artur,
Thank you for your reply. I have assigned the properties of a tension only member and as expected the utilisations have fallen to acceptable levels.
Another point with the model is that it reports a "Stability error (Type 3)". I have tried to attach a zipped version of the model without results but the file size is to large (2 MB). Can I further reduce the file size or send in another way?
Thanks,
Graham
Thank you Artur. The model is located at the following link:
1. Delete releases from truss bars
2. Correct roof using the detailed correction to planes.
https://www.filemail.com/dl.aspx?id=FVGPFTIEBDRPYCO
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Hi Artur,
I followed your instructions and now have the model analysing with no errors reported. I also chose to represent the bracing members as "truss bars" rather than tension only members.
Thank you for your help,
Graham
I also chose to represent the bracing members as "truss bars" rather than tension only members.
If they are supposed to transfer both compression and tension then this is correct. If you don't want them to work under compression then you should use tension only.
Take a look at the topic: http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Collecting-phases/td-p/3505898
maybe it will also help you about your question.
Can you please advise what's better in regard of robot's interpretation of braces: to define braces as truss members (tension\compression) or set end releases to the bracing member?
Up to you.
But in case of having convergence problems with tension \ compression only bars it is recommended to replace them by unidirectional relases:
http://help.autodesk.com/view/RSAPRO/2016/ENU/?guid=GUID-A65C66FB-20DA-4B7C-BFE2-3A7B0CF54F7E
How would one go about excluding members from the self-weight load list?
Thanks